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  • Address book with C programming; cannot compile my code.

    - by osabri
    I've divided my code into small programs so it can be easy to excute /* ab_error.c : in case of errors following messages will be displayed */ #include "adressbook.h" static char *errormsg[] = { "", "\nNot enough space on disk", "\nCannot open file", "\nCannot read file", "\nCannot write file" }; void check(int error) { switch(error) { case 0: return; case 1: write_file(); case 2: case 3: case 4: system("cls"); fputs(errormsg[error], stderr); exit(error); } } 2nd /* ab_fileio.c : functions for file input/output */ #include "adressbook.h" static char ab_file[] = "ADRESSBOOK.DAT"; //file to save the entries int read_file(void) { int error = 0; FILE *fp; ELEMENT *new_e, *last_e = NULL; DATA buffer; if( (fp = fopen(ab_file, "rb")) == NULL) return -1; //no file found while (fread(&buffer, sizeof(DATA), 1, fp) == 1) //reads one list element after another { if( (new_e = make_element()) == NULL) { error = 1; break; //not enough space } new_e->person = buffer; //copy data to new element new_e->next = NULL; if(hol.first == NULL) //list is empty? hol.first = new_e; //yes else last_e->next = new_e; //no last_e = new_e; ++hol.amount; } if( !error && !feof(fp) ) error = 3; //cannot read file fclose(fp); return error; } /*-------------------------------*/ int write_file(void) { int error = 0; FILE *fp; ELEMENT *p; if( (p = hol.first) == NULL) return 0; //list is empty if( (fp = fopen(ab_file, "wb")) == NULL) return 2; //cannot open while( p!= NULL) { if( fwrite(&p->person, sizeof(DATA), 1, fp) < 1) { error = 4; break; //cannot write } p = p->next; } fclose(fp); return error; } 3rd /* ab_list.c : functions to manipulate the list */ #include "adressbook.h" HOL hol = {0, NULL}; //global definition for head of list /* -------------------- */ ELEMENT *make_element(void) { return (ELEMENT *)malloc( sizeof(ELEMENT) ); } /* -------------------- */ int ins_element( DATA *newdata) { ELEMENT *new_e, *pre_p; if((new_e = make_element()) == NULL) return 1; new_e ->person = *newdata; // copy data to new element pre_p = search(new_e->person.family_name); if(pre_p == NULL) //no person in list { new_e->next = hol.first; //put it to the begin hol.first = new_e; } else { new_e->next = pre_p->next; pre_p->next = new_e; } ++hol.amount; return 0; } int erase_element( char name, char surname ) { return 0; } /* ---------------------*/ ELEMENT *search(char *name) { ELEMENT *sp, *retp; //searchpointer, returnpointer retp = NULL; sp = hol.first; while(sp != NULL && sp->person.family_name != name) { retp = sp; sp = sp->next; } return(retp); } 4th /* ab_screen.c : functions for printing information on screen */ #include "adressbook.h" #include <conio.h> #include <ctype.h> /* standard prompts for in- and output */ static char pgmname[] = "---- Oussama's Adressbook made in splendid C ----"; static char options[] = "\ 1: Enter new adress\n\n\ 2: Delete entry\n\n\ 3: Change entry\n\n\ 4: Print adress\n\n\ Esc: Exit\n\n\n\ Your choice . . .: "; static char prompt[] = "\ Name . . . .:\n\ Surname . . :\n\n\ Street . . .:\n\n\ House number:\n\n\ Postal code :\n\n\ Phone number:"; static char buttons[] = "\ <Esc> = cancel input <Backspace> = correct input\ <Return> = assume"; static char headline[] = "\ Name Surname Street House Postal code Phone number \n\ ------------------------------------------------------------------------"; static char further[] = "\ -------- continue with any key --------"; /* ---------------------------------- */ int menu(void) //show menu and read user input { int c; system ("cls"); set_cur(0,20); puts(pgmname); set_cur(6,0); printf("%s", options); while( (c = getch()) != ESC && (c < '1' || c > '4')) putch('\a'); return c; } /* ---------------------------------- */ int print_adr_book(void) //display adressbook { int line = 1; ELEMENT *p = hol.first; system("cls"); set_cur(0,20); puts(pgmname); set_cur(2,0); puts(headline); set_cur(5,0); while(p != NULL) //run through list and show entries { printf("%5d %-15s ",line, p->person.family_name); printf("%-12s %-15s ", p->person.given_name, p->person.street); printf("%-4d %-5d %-12d\n",p->person.house_number, p->person.postal_code, p->person.phone); p = p->next; if( p == NULL || ++line %16 == 1) //end of list or screen is full { set_cur(24,0); printf("%s",further); if( getch() == ESC) return 0; set_cur(5,0); scroll_up(0,5,24);//puts(headline); } } return 0; } /* -------------------------------------------*/ int make_entry(void) { char cache[50]; DATA newperson; ELEMENT *p; while(1) { system("cls"); set_cur(0,20); puts(pgmname); set_cur(6,0); puts("Please enter new data:"); set_cur(10,0); puts(prompt); set_cur(24,0); printf("%s",buttons); balken(10, 25, MAXL, ' ',0x70); //input name if(input(newperson.family_name, MAXL, ESC, CR) == ESC) return 0; balken(12,25, MAXL, ' ', 0x70); //surname if(input(newperson.given_name, MAXL, ESC, CR) == ESC) return 0; balken(14,25, 30, ' ', 0x70); //street if(input(newperson.street, 30, ESC, CR) == ESC) return 0; balken(16,25, 4, ' ',0x70); //housenumber if(input(cache, 4, ESC, CR) == ESC) return 0; newperson.house_number = atol(cache); //to string balken(18,25, 5, ' ',0x70); //postal code if(input(cache, 5, ESC, CR) == ESC) return 0; newperson.postal_code = atol(cache); //to string balken(20,25, 20, ' ',0x70); //phone number if(input(cache, 20, ESC, CR) == ESC) return 0; newperson.phone = atol(cache); //to string p = search(newperson.phone); if( p!= NULL && p->person.phone == newperson.phone) { set_cur(22,25); puts("phonenumber already exists!"); set_cur(24,0); printf("%s, further"); getch(); continue; } } } 5th /* adress_book_project.c : main program to create an adressbook */ /* copyrights by Oussama Sabri, June 2010 */ #include "adressbook.h" //project header file int main() { int rv, cmd; //return value, user command if ( (rv = read_file() ) == -1) // no data saved yet rv = make_entry(); check(rv); //prompts an error and quits program on disfunction do { switch (cmd = menu())//calls menu and gets user input back { case '1': rv = make_entry(); break; case '2': //delete entry case '3': //changes entry rv = change_entry(cmd); break; case '4': //prints adressbook on screen rv = print_adr_book(); break; case ESC: //end of program system ("cls"); rv = 0; break; } }while(cmd!= ESC); check ( write_file() ); //save adressbook return 0; } 6th /* Getcb.c --> Die Funktion getcb() liefert die naechste * * Tastatureingabe (ruft den BIOS-INT 0x16 auf). * * Return-Wert: * * ASCII-Code bzw. erweiterter Code + 256 */ /* Hinweis: Es muss ein DOS-Compiler verwendet werden. * * (z.B. der GNU-Compiler fuer DOS auf der CD) */ #include <dos.h> int getcb(void) { union REGS intregs; intregs.h.ah = 0; // Subfunktion 0: ein Zeichen // von der Tastatur lesen. int86( 0x16, &intregs, &intregs); if( intregs.h.al != 0) // Falls ASCII-Zeichen, return (intregs.h.al); // dieses zurueckgeben. else // Sonst den erweiterten return (intregs.h.ah + 0x100); // Code + 256 } 7th /* PUTCB.C --> enthaelt die Funktionen * * - putcb() * * - putcb9() * * - balken() * * - input() * * * * Es werden die Funktionen 9 und 14 des Video-Interrupts * * (ROM-BIOS-Interrupt 0x10) verwendet. * * * * Die Prototypen dieser Funktionen stehen in BIO.H */ /* Hinweis: Es muss ein DOS-Compiler verwendet werden. * * (z.B. der GNU-Compiler fuer DOS auf der CD) */ #include <dos.h> #define VIDEO_INT 0x10 /*---------------------------------------------------------------- * putcb(c) gibt das Zeichen auf der aktuellen Cursor-Position * am Bildschirm aus. Der Cursor wird versetzt. * Steuerzeichen Back-Space, CR, LF und BELL werden * ausgefuehrt. * Return-Wert: keiner */ void putcb(unsigned char c) /* Gibt das Zeichen in c auf */ { /* den Bildschirm aus. */ union REGS intregs; intregs.h.ah = 14; /* Subfunktion 14 ("Teletype") */ intregs.h.al = c; intregs.h.bl = 0xf; /* Vordergrund-Farbe im */ /* Grafik-Modus. */ int86(VIDEO_INT, &intregs, &intregs); } /*---------------------------------------------------------------- * putcb9(c,count,mode) gibt das Zeichen in c count-mal im * angegebenen Modus auf der aktuellen * Cursor-Position am Bildschirm aus. * Der Cursor wird nicht versetzt. * * Return-Wert: keiner */ void putcb9( unsigned char c, /* das Zeichen */ unsigned count, /* die Anzahl */ unsigned mode ) /* Low-Byte: das Atrribut */ { /* High-Byte: die Bildschirmseite*/ union REGS intregs; intregs.h.ah = 9; /* Subfunktion 9 des Int 0x10 */ intregs.h.al = c; intregs.x.bx = mode; intregs.x.cx = count; int86( VIDEO_INT, &intregs, &intregs); } /*---------------------------------------------------------------- * balken() positioniert den Cursor und zeichnet einen Balken, * wobei Position, L„nge, Fllzeichen und Attribut * als Argumente bergeben werden. * Der Cursor bleibt auf der ersten Position im Balken. */ void balken( unsigned int zeile, /* Start-Position */ unsigned int spalte, unsigned int laenge, /* Laenge des Balkens */ unsigned char c, /* Fuellzeichen */ unsigned int modus) /* Low-Byte: Attribut */ /* High-Byte: Bildschirmseite */ { union REGS intregs; intregs.h.ah = 2; /* Cursor auf der angegebenen */ intregs.h.dh = zeile; /* Bildschirmseite versetzen. */ intregs.h.dl = spalte; intregs.h.bh = (modus >> 8); int86(VIDEO_INT, &intregs, &intregs); putcb9(c, laenge, modus); /* Balken ausgeben. */ } /*---------------------------------------------------------------- * input() liest Zeichen von der Tastatur ein und haengt '\0' an. * Mit Backspace kann die Eingabe geloescht werden. * Das Attribut am Bildschirm bleibt erhalten. * * Argumente: 1. Zeiger auf den Eingabepuffer. * 2. Anzahl maximal einzulesender Zeichen. * 3. Die optionalen Argumente: Zeichen, mit denen die * Eingabe abgebrochen werden kann. * Diese Liste muá mit CR = '\r' enden! * Return-Wert: Das Zeichen, mit dem die Eingabe abgebrochen wurde. */ #include <stdarg.h> int getcb( void); /* Zum Lesen der Tastatur */ int input(char *puffer, int max,... ) { int c; /* aktuelles Zeichen */ int breakc; /* Abruchzeichen */ int nc = 0; /* Anzahl eingelesener Zeichen */ va_list argp; /* Zeiger auf die weiteren Arumente */ while(1) { *puffer = '\0'; va_start(argp, max); /* argp initialisieren */ c = getcb(); do /* Mit Zeichen der Abbruchliste vergleichen */ if(c == (breakc = va_arg(argp,int)) ) return(breakc); while( breakc != '\r' ); va_end( argp); if( c == '\b' && nc > 0) /* Backspace? */ { --nc; --puffer; putcb(c); putcb(' '); putcb(c); } else if( c >= 32 && c <= 255 && nc < max ) { ++nc; *puffer++ = c; putcb(c); } else if( nc == max) putcb('\7'); /* Ton ausgeben */ } } 8th /* Video.c --> Enthaelt die Funktionen * cls(), * scroll_up(), scroll_down(), * set_cur(), get_cur(), * set_screen_page(), get_screen_page() * * Die Prototypen dieser Funktionen befinden sich in BIO.H */ /* Hinweis: Es muss ein DOS-Compiler verwendet werden. * * (z.B. der GNU-Compiler fuer DOS auf der CD) */ #include <dos.h> #include "bio.h" #define VIDEO_INT 0x10 typedef unsigned char BYTE; void scroll_up( int anzahl, int anf_zeile, int end_zeile) { /* Fenster hoch rollen. */ union REGS intregs; intregs.x.ax = 0x600 + anzahl; /* Subfunktion AH = 6, */ /* AL = Anzahl Zeilen. */ intregs.x.cx = anf_zeile << 8; /* CH=anf_zeile, cl=0 */ intregs.x.dx = (end_zeile <<8) | 79; /* DH=end_zeile,DL=79 */ intregs.h.bh = 7; /* normales Attribut */ int86(VIDEO_INT, &intregs, &intregs); } void scroll_down( int anzahl, int anf_zeile, int end_zeile) { /* Fenster runter rollen. */ union REGS intregs; intregs.x.ax = 0x700 + anzahl; /* Subfunktion AH = 7, */ /* AL = Anzahl Zeilen. */ intregs.x.cx = anf_zeile << 8; /* CH=anf_zeile, cl=0 */ intregs.x.dx = (end_zeile <<8) | 79; /* DH=end_zeile,DL=79 */ intregs.h.bh = 7; /* normales Attribut */ int86(VIDEO_INT, &intregs, &intregs); } void set_cur( int zeile, int spalte) /* versetzt den Cursor */ { /* der aktuellen Bildschirmseite.*/ union REGS intregs; intregs.h.ah = 2; intregs.h.dh = (BYTE)zeile; intregs.h.dl = (BYTE)spalte; intregs.h.bh = (BYTE)get_screen_page(); int86(VIDEO_INT, &intregs, &intregs); } void get_cur(int *zeile, int *spalte) /* holt die Cursor- */ { /* Position der aktuellen Bildschirmseite.*/ union REGS intregs; intregs.h.ah = 3; intregs.h.bh = (BYTE)get_screen_page(); int86(VIDEO_INT, &intregs, &intregs); *zeile = (unsigned)intregs.h.dh; *spalte = (unsigned)intregs.h.dl; } void cls(void) { scroll_up(0,0,24); /* Gesamten Bildschirm loeschen. */ set_cur(0,0); /* Cursor in Home-Position. */ } int get_screen_page(void) /* Aktuelle Bildschirmseite holen.*/ { union REGS intregs; intregs.h.ah = 15; /* Subfunktion AH = 15: */ /* Bildschirm-Modus feststellen. */ int86(VIDEO_INT, &intregs, &intregs); return (intregs.h.bh); } void set_screen_page(int seite) /* setzt die aktive Seite des */ { /* Bildschirmpuffers auf die */ /* angegebene Seite. */ union REGS intregs; intregs.x.ax = 0x500 + seite; /* Subfunktion AH = 5 */ int86(VIDEO_INT, &intregs, &intregs); } /* ------------------------------------------------------------- Ein kleines Testprogramm : */ /* #include <stdio.h> int main() { cls(); set_cur(23, 0); printf("Weiter mit <Return>\n"); set_cur(12, 20); printf("Ein Test!\n"); getchar(); scroll_up(3, 5, 20); getchar(); scroll_down(6, 5, 20); getchar(); set_screen_page(1); printf("\nAuf der 2. Seite !\n"); getchar(); set_screen_page(0); set_cur(0,0); printf("\nWieder auf der 1. Seite !\n"); getchar(); cls(); return 0; } */ /* Video.c --> Enthaelt die Funktionen * cls(), * scroll_up(), scroll_down(), * set_cur(), get_cur(), * set_screen_page(), get_screen_page() * * Die Prototypen dieser Funktionen befinden sich in BIO.H */ /* Hinweis: Es muss ein DOS-Compiler verwendet werden. * * (z.B. der GNU-Compiler fuer DOS auf der CD) */ #include <dos.h> #include "bio.h" #define VIDEO_INT 0x10 typedef unsigned char BYTE; void scroll_up( int anzahl, int anf_zeile, int end_zeile) { /* Fenster hoch rollen. */ union REGS intregs; intregs.x.ax = 0x600 + anzahl; /* Subfunktion AH = 6, */ /* AL = Anzahl Zeilen. */ intregs.x.cx = anf_zeile << 8; /* CH=anf_zeile, cl=0 */ intregs.x.dx = (end_zeile <<8) | 79; /* DH=end_zeile,DL=79 */ intregs.h.bh = 7; /* normales Attribut */ int86(VIDEO_INT, &intregs, &intregs); } void scroll_down( int anzahl, int anf_zeile, int end_zeile) { /* Fenster runter rollen. */ union REGS intregs; intregs.x.ax = 0x700 + anzahl; /* Subfunktion AH = 7, */ /* AL = Anzahl Zeilen. */ intregs.x.cx = anf_zeile << 8; /* CH=anf_zeile, cl=0 */ intregs.x.dx = (end_zeile <<8) | 79; /* DH=end_zeile,DL=79 */ intregs.h.bh = 7; /* normales Attribut */ int86(VIDEO_INT, &intregs, &intregs); } void set_cur( int zeile, int spalte) /* versetzt den Cursor */ { /* der aktuellen Bildschirmseite.*/ union REGS intregs; intregs.h.ah = 2; intregs.h.dh = (BYTE)zeile; intregs.h.dl = (BYTE)spalte; intregs.h.bh = (BYTE)get_screen_page(); int86(VIDEO_INT, &intregs, &intregs); } void get_cur(int *zeile, int *spalte) /* holt die Cursor- */ { /* Position der aktuellen Bildschirmseite.*/ union REGS intregs; intregs.h.ah = 3; intregs.h.bh = (BYTE)get_screen_page(); int86(VIDEO_INT, &intregs, &intregs); *zeile = (unsigned)intregs.h.dh; *spalte = (unsigned)intregs.h.dl; } void cls(void) { scroll_up(0,0,24); /* Gesamten Bildschirm loeschen. */ set_cur(0,0); /* Cursor in Home-Position. */ } int get_screen_page(void) /* Aktuelle Bildschirmseite holen.*/ { union REGS intregs; intregs.h.ah = 15; /* Subfunktion AH = 15: */ /* Bildschirm-Modus feststellen. */ int86(VIDEO_INT, &intregs, &intregs); return (intregs.h.bh); } void set_screen_page(int seite) /* setzt die aktive Seite des */ { /* Bildschirmpuffers auf die */ /* angegebene Seite. */ union REGS intregs; intregs.x.ax = 0x500 + seite; /* Subfunktion AH = 5 */ int86(VIDEO_INT, &intregs, &intregs); } /* ------------------------------------------------------------- Ein kleines Testprogramm : */ /* #include <stdio.h> int main() { cls(); set_cur(23, 0); printf("Weiter mit <Return>\n"); set_cur(12, 20); printf("Ein Test!\n"); getchar(); scroll_up(3, 5, 20); getchar(); scroll_down(6, 5, 20); getchar(); set_screen_page(1); printf("\nAuf der 2. Seite !\n"); getchar(); set_screen_page(0); set_cur(0,0); printf("\nWieder auf der 1. Seite !\n"); getchar(); cls(); return 0; } */ /* BIO.H --> Enthaelt die Prototypen der BIOS-Funktionen. */ /* --- Funktionen in VIDEO.C --- */ extern void scroll_up(int anzahl, int anf_zeile,int end_zeile); extern void scroll_down(int anzahl, int anf_zeile, int end_zeile); extern void set_cur(int zeile, int spalte); extern void get_cur(int *zeile, int *spalte); extern void cls(void); extern int get_screen_page(void); extern void set_screen_page(int page); /* --- Funktionen in GETCB.C / PUTCB.C --- */ extern int getcb(void); extern void putcb(int c); extern void putcb9(int c, unsigned count, unsigned modus); extern void balken(int zeile, int spalte, int laenge, int c, unsigned modus); extern int input(char *puffer, int max,... ); need your help, can't find my mistakes:((

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  • Possible to use Python with Intel's Atom Developer SDK (C/C++)?

    - by Jordan Magnuson
    So I've made a game in Python and PyGame. Now I'm interested in submitting the game to Intel's March Developer Challenge. However, the developer challenge requires use of Intel's Atom Developer SDK (http://appdeveloper.intel.com/en-us/sdk), which only has API's for C and C++. I'm new to Python and PyGame, and have no experience in C or C++. My question is, would it be possible to somehow implement Intel's Atom SDK through/with/from a Python application (as the first link above suggests)? I've read up a little bit on embedding/extending Python into/with C, but I'm not entirely sure what to embed or where. I mean, I know I can do things like this in C: #include <Python.h> int main(int argc, char *argv[]) { Py_Initialize(); PyRun_SimpleString("from time import time,ctime\n" "print 'Today is',ctime(time())\n"); Py_Finalize(); return 0; } But what do I do about all my dependencies on Python and Pygame, for people that don't have those installed on their machines? Normally Py2Exe takes care of compacting the required dependencies (I've managed to package my game into an exe/zip), but how do I take care of that stuff in the context of embedding within C? Can I somehow work with py2exe on this, or do I need to do something entirely different for embedding within C? It seems like it would be a lot easier to go the route of extending Python with the C validation code, rather than trying to embed my whole game within C, but I think that's not an option, "because the library provided is currently only available as a Visual Studio 2008 '.lib'", meaning the application has to be compiled with Visual Studio...? Any help, thoughts, or ideas are much appreciated! You can find the complete SDK Developer's Guide on the intel site above, but here is their "Hello World" using the C Language API: #include <stdio.h> #include “adpcore.h” int main( int argc, char* argv[] ) { ADP_RET_CODE ret_code; const ADP_APPLICATIONID myApplicationID = {{ 0x12345678,0x11112222,0x33331234,0x567890ab}}; if ((ret_code = ADP_Initialize()) != ADP_SUCCESS ){ printf( “ERROR: exiting” ); exit( -1 ); } if (( ret_code = ADP_IsAuthorized( myApplicationId )) == ADP_AUTHORIZED ) printf( “Hello World” ); else printf( “Not authorized to run” ); exit 0; } 35 Page SDK Developer Guide: http:// appdeveloper.intel.com/sites/files/pages/SDK%20Developer%20Guide.pdf

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  • Calculating CPU frequency in C with RDTSC always returns 0

    - by Nazgulled
    Hi, The following piece of code was given to us from our instructor so we could measure some algorithms performance: #include <stdio.h> #include <unistd.h> static unsigned cyc_hi = 0, cyc_lo = 0; static void access_counter(unsigned *hi, unsigned *lo) { asm("rdtsc; movl %%edx,%0; movl %%eax,%1" : "=r" (*hi), "=r" (*lo) : /* No input */ : "%edx", "%eax"); } void start_counter() { access_counter(&cyc_hi, &cyc_lo); } double get_counter() { unsigned ncyc_hi, ncyc_lo, hi, lo, borrow; double result; access_counter(&ncyc_hi, &ncyc_lo); lo = ncyc_lo - cyc_lo; borrow = lo > ncyc_lo; hi = ncyc_hi - cyc_hi - borrow; result = (double) hi * (1 << 30) * 4 + lo; return result; } However, I need this code to be portable to machines with different CPU frequencies. For that, I'm trying to calculate the CPU frequency of the machine where the code is being run like this: int main(void) { double c1, c2; start_counter(); c1 = get_counter(); sleep(1); c2 = get_counter(); printf("CPU Frequency: %.1f MHz\n", (c2-c1)/1E6); printf("CPU Frequency: %.1f GHz\n", (c2-c1)/1E9); return 0; } The problem is that the result is always 0 and I can't understand why. I'm running Linux (Arch) as guest on VMware. On a friend's machine (MacBook) it is working to some extent; I mean, the result is bigger than 0 but it's variable because the CPU frequency is not fixed (we tried to fix it but for some reason we are not able to do it). He has a different machine which is running Linux (Ubuntu) as host and it also reports 0. This rules out the problem being on the virtual machine, which I thought it was the issue at first. Any ideas why this is happening and how can I fix it?

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  • GCC, -O2, and bitfields - is this a bug or a feature?

    - by Rooke
    Today I discovered alarming behavior when experimenting with bit fields. For the sake of discussion and simplicity, here's an example program: #include <stdio.h> struct Node { int a:16 __attribute__ ((packed)); int b:16 __attribute__ ((packed)); unsigned int c:27 __attribute__ ((packed)); unsigned int d:3 __attribute__ ((packed)); unsigned int e:2 __attribute__ ((packed)); }; int main (int argc, char *argv[]) { Node n; n.a = 12345; n.b = -23456; n.c = 0x7ffffff; n.d = 0x7; n.e = 0x3; printf("3-bit field cast to int: %d\n",(int)n.d); n.d++; printf("3-bit field cast to int: %d\n",(int)n.d); } The program is purposely causing the 3-bit bit-field to overflow. Here's the (correct) output when compiled using "g++ -O0": 3-bit field cast to int: 7 3-bit field cast to int: 0 Here's the output when compiled using "g++ -O2" (and -O3): 3-bit field cast to int: 7 3-bit field cast to int: 8 Checking the assembly of the latter example, I found this: movl $7, %esi movl $.LC1, %edi xorl %eax, %eax call printf movl $8, %esi movl $.LC1, %edi xorl %eax, %eax call printf xorl %eax, %eax addq $8, %rsp The optimizations have just inserted "8", assuming 7+1=8 when in fact the number overflows and is zero. Fortunately the code I care about doesn't overflow as far as I know, but this situation scares me - is this a known bug, a feature, or is this expected behavior? When can I expect gcc to be right about this? Edit (re: signed/unsigned) : It's being treated as unsigned because it's declared as unsigned. Declaring it as int you get the output (with O0): 3-bit field cast to int: -1 3-bit field cast to int: 0 An even funnier thing happens with -O2 in this case: 3-bit field cast to int: 7 3-bit field cast to int: 8 I admit that attribute is a fishy thing to use; in this case it's a difference in optimization settings I'm concerned about.

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  • Is O_NONBLOCK being set a property of the file descriptor or underlying file?

    - by Daniel Trebbien
    From what I have been reading on The Open Group website on fcntl, open, read, and write, I get the impression that whether O_NONBLOCK is set on a file descriptor, and hence whether non-blocking I/O is used with the descriptor, should be a property of that file descriptor rather than the underlying file. Being a property of the file descriptor means, for example, that if I duplicate a file descriptor or open another descriptor to the same file, then I can use blocking I/O with one and non-blocking I/O with the other. Experimenting with a FIFO, however, it appears that it is not possible to have a blocking I/O descriptor and non-blocking I/O descriptor to the FIFO simultaneously (so whether O_NONBLOCK is set is a property of the underlying file [the FIFO]): #include <errno.h> #include <fcntl.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main(int argc, char **argv) { int fds[2]; if (pipe(fds) == -1) { fprintf(stderr, "`pipe` failed.\n"); return EXIT_FAILURE; } int fd0_dup = dup(fds[0]); if (fd0_dup <= STDERR_FILENO) { fprintf(stderr, "Failed to duplicate the read end\n"); return EXIT_FAILURE; } if (fds[0] == fd0_dup) { fprintf(stderr, "`fds[0]` should not equal `fd0_dup`.\n"); return EXIT_FAILURE; } if ((fcntl(fds[0], F_GETFL) & O_NONBLOCK)) { fprintf(stderr, "`fds[0]` should not have `O_NONBLOCK` set.\n"); return EXIT_FAILURE; } if (fcntl(fd0_dup, F_SETFL, fcntl(fd0_dup, F_GETFL) | O_NONBLOCK) == -1) { fprintf(stderr, "Failed to set `O_NONBLOCK` on `fd0_dup`\n"); return EXIT_FAILURE; } if ((fcntl(fds[0], F_GETFL) & O_NONBLOCK)) { fprintf(stderr, "`fds[0]` should still have `O_NONBLOCK` unset.\n"); return EXIT_FAILURE; // RETURNS HERE } char buf[1]; if (read(fd0_dup, buf, 1) != -1) { fprintf(stderr, "Expected `read` on `fd0_dup` to fail immediately\n"); return EXIT_FAILURE; } else if (errno != EAGAIN) { fprintf(stderr, "Expected `errno` to be `EAGAIN`\n"); return EXIT_FAILURE; } return EXIT_SUCCESS; } This leaves me thinking: is it ever possible to have a non-blocking I/O descriptor and blocking I/O descriptor to the same file and if so, does it depend on the type of file (regular file, FIFO, block special file, character special file, socket, etc.)?

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  • FSM spellchecker

    - by Durell
    I would love to have a debugged copy of the finite state machine code below. I tried debugging but could not, all the machine has to do is to spell check the word "and",an equivalent program using case is welcomed. #include<cstdlib> #include<stdio.h> #include<string.h> #include<iostream> #include<string> using namespace std; char in_str; int n; void spell_check() { char data[256]; int i; FILE *in_file; in_file=fopen("C:\\Users\\mytorinna\\Desktop\\a.txt","r+"); while (!feof(in_file)) { for(i=0;i<256;i++) { fscanf(in_file,"%c",in_str); data[i]=in_str; } //n = strlen(in_str); //start(data); cout<<data; } } void start(char data) { // char next_char; //int i = 0; // for(i=0;i<256;i++) // if (n == 0) { if(data[i]="a") { state_A(); exit; } else { cout<<"I am comming"; } // cout<<"This is an empty string"; // exit();//do something here to terminate the program } } void state_A(int i) { if(in_str[i] == 'n') { i++; if(i<n) state_AN(i); else error(); } else error(); } void state_AN(int i) { if(in_str[i] == 'd') { if(i == n-1) cout<<" Your keyword spelling is correct"; else cout<<"Wrong keyword spelling"; } } int main() { spell_check(); system("pause"); return 0; }

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  • The MYSTERY SPIRAL

    - by CVS26
    Problem statement: Given a integer N, print N*N numbers in a N x N spiral Detailed problem description: http://2600hertz.wordpress.com/2010/03/20/the-mystery-spiral/ Solution: Recently posted the following code. (managed to compress it into as few as 99 lines...) //File : spiral.c // //INPUT : Size of spiral (N) //OUTPUT : Numbers printed in a N x N spiral #include <stdio.h> #include <conio.h> #include <stdlib.h> void main() { int N; clrscr(); //get input no. N printf("\nEnter size of Matrix: "); scanf("%d",&N); //Allocate reqd. memory int* matrix_ptr= (int*)malloc(N*N); //Filling the Matrix spirally int curr_val=N*N; int* curr_ptr=matrix_ptr; int curr_level=N; while(curr_level>1) { //curr_level-1 elements horizontally //from left to right for(int x=0;x<curr_level-1;x++) { *curr_ptr=curr_val; curr_val--; curr_ptr++; } //curr_level-1 elements vertically //from top to bottom for(int y=0;y<curr_level-1;y++) { *curr_ptr=curr_val; curr_val--; curr_ptr+=N; } //curr_level-1 elements horizontally //from right to left for(int z=0;z<curr_level-1;z++) { *curr_ptr=curr_val; curr_val--; curr_ptr--; } //curr_level-1 element vertically //from bottom to top for(int w=0;w<curr_level-1;w++) { *curr_ptr=curr_val; curr_val--; curr_ptr-=N; } //Next curr_ptr+=N+1; curr_level-=2; } *curr_ptr=curr_val; //routine to print the matrix printf("\n\n\n\n\n"); for( int i=0;i<N;i++) { for( int j=0;j<N;j++) { printf("%d\t",*(matrix_ptr+(i*N+j))); } printf("\n"); } getch(); } Please comment on further optimisations (if any)...

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  • conversion of DNA to Protein - c structure issue

    - by sam
    I am working on conversion of DNA sequence to Protein sequence. I had completed all program only one error I found there is of structure. dna_codon is a structure and I am iterating over it.In first iteration it shows proper values of structure but from next iteration, it dont show the proper value stored in structure. Its a small error so do not think that I havnt done anything and downvote. I am stucked here because I am new in c for structures. CODE : #include <stdio.h> #include<string.h> void main() { int i, len; char short_codons[20]; char short_slc[1000]; char sequence[1000]; struct codons { char amino_acid[20], slc[20], dna_codon[40]; }; struct codons c1 [20]= { {"Isoleucine", "I", "ATT, ATC, ATA"}, {"Leucine", "L", "CTT, CTC, CTA, CTG, TTA, TTG"}, {"Valine", "V", "GTT, GTC, GTA, GTG"}, {"Phenylalanine", "F", "TTT, TTC"}, {"Methionine", "M", "ATG"}, {"Cysteine", "C", "TGT, TGC"}, {"Alanine", "A", "GCT, GCC, GCA, GCG"}, {"Proline", "P", "CCT, CCC, CCA,CCG "}, {"Threonine", "T", "ACT, ACC, ACA, ACG"}, {"Serine", "S", "TCT, TCC, TCA, TCG, AGT, AGC"}, {"Tyrosine", "Y", "TAT, TAC"}, {"Tryptophan", "W", "TGG"}, {"Glutamine", "Q", "CAA, CAG"}, {"Aspargine","N" "AAT, AAC"}, {"Histidine", "H", "CAT, CAC"}, {"Glutamic acid", "E", "GAA, GAG"}, {"Aspartic acid", "D", "GAT, GAC"}, {"Lysine", "K", "AAA, AAG"}, {"Arginine", "R", "CGT, CGC, CGA, CGG, AGA, AGG"}, {"Stop codons", "Stop", "AA, TAG, TGA"} }; int count = 0; printf("Enter the sequence: "); gets(sequence); char *input_string = sequence; char *tmp_str = input_string; int k; char *pch; while (*input_string != '\0') { char string_3l[4] = {'\0'}; strncpy(string_3l, input_string, 3); printf("\n-----------%s & %s----------", string_3l, tmp_str ); for(k=0;k<20;k++) { //printf("@REAL - %s", c1[0].dna_codon); printf("@ %s", c1[k].dna_codon); int x; x = c1[k].dna_codon; pch = strtok(x, ","); while (pch != NULL) { printf("\n%d : %s with %s", k, string_3l, pch); count=strcmp(string_3l, pch); if(count==0) { strcat(short_slc, c1[k].slc); printf("\n==>%s", short_slc); } pch = strtok (NULL, " ,.-"); } } input_string = input_string+3; } printf("\nProtien sequence is : %s\n", short_slc); } INPUT : TAGTAG OUTPUT : If you see output of printf("\n-----------%s & %s----------", string_3l, tmp_str ); in both iterations, we found that values defined in structure are reduced. I want to know why structure reduces it or its my mistake? because I am stucked here

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  • Sening a file from memory (rather than disk) over HTTP using libcurl

    - by cinek1lol
    Hi! I would like to send pictures via a program written in C + +. - OK WinExec("C:\\curl\\curl.exe -H Expect: -F \"fileupload=@C:\\curl\\ok.jpg\" -F \"xml=yes\" -# \"http://www.imageshack.us/index.php\" -o data.txt -A \"Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.1) Gecko/20061204 Firefox/2.0.0.1\" -e \"http://www.imageshack.us\"", NULL); It works, but I would like to send the pictures from pre-loaded carrier to a variable char (you know what I mean? First off, I load the pictures into a variable and then send the variable), cause now I have to specify the path of the picture on a disk. I wanted to write this program in c++ by using the curl library, not through exe. extension. I have also found such a program (which has been modified by me a bit) #include <stdio.h> #include <string.h> #include <iostream> #include <curl/curl.h> #include <curl/types.h> #include <curl/easy.h> int main(int argc, char *argv[]) { CURL *curl; CURLcode res; struct curl_httppost *formpost=NULL; struct curl_httppost *lastptr=NULL; struct curl_slist *headerlist=NULL; static const char buf[] = "Expect:"; curl_global_init(CURL_GLOBAL_ALL); /* Fill in the file upload field */ curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "send", CURLFORM_FILE, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "nowy.jpg", CURLFORM_COPYCONTENTS, "nowy.jpg", CURLFORM_END); curl_formadd(&formpost, &lastptr, CURLFORM_COPYNAME, "submit", CURLFORM_COPYCONTENTS, "send", CURLFORM_END); curl = curl_easy_init(); headerlist = curl_slist_append(headerlist, buf); if(curl) { curl_easy_setopt(curl, CURLOPT_URL, "http://www.imageshack.us/index.php"); if ( (argc == 2) && (!strcmp(argv[1], "xml=yes")) ) curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist); curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost); res = curl_easy_perform(curl); curl_easy_cleanup(curl); curl_formfree(formpost); curl_slist_free_all (headerlist); } system("pause"); return 0; }

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  • More GCC link time issues: undefined reference to main

    - by vikramtheone
    Hi Guys, I'm writing software for a Cortex-A8 processor and I have to write some ARM assembly code to access specific registers. I'm making use of the gnu compilers and related tool chains, these tools are installed on the processor board(Freescale i.MX515) with Ubuntu. I make a connection to it from my host PC(Windows) using WinSCP and the PuTTY terminal. As usual I started with a simple C project having main.c and functions.s. I compile the main.c using GCC, assemble the functions.s using as and link the generated object files using once again GCC, but I get strange errors during this process. An important finding - Meanwhile, I found out that my assembly code may have some issues because when I individually assemble it using the command as -o functions.o functions.s and try running the generated functions.o using ./functions.o command, the bash shell is failing to recognize this file as an executable(on pressing tab functions.o is not getting selected/PuTTY is not highlighting the file). Can anyone suggest whats happening here? Are there any specific options I have to send, to GCC during the linking process? The errors I see are strange and beyond my understanding, I don't understand to what the GCC is referring. I'm pasting here the contents of main.c, functions.s, the Makefile and the list of errors. Help, please!!! Vikram main.c #include <stdio.h> #include <stdlib.h> int main(void) { puts("!!!Hello World!!!"); /* prints !!!Hello World!!! */ return EXIT_SUCCESS; } functions.s * Main program */ .equ STACK_TOP, 0x20000800 .text .global _start .syntax unified _start: .word STACK_TOP, start .type start, function start: movs r0, #10 movs r1, #0 .end Makefile all: hello hello: main.o functions.o gcc -o main.o functions.o main.o: main.c gcc -c -mcpu=cortex-a8 main.c functions.o: functions.s as -mcpu=cortex-a8 -o functions.o functions.s Errors ubuntu@ubuntu-desktop:~/Documents/Project/Others/helloworld$ make gcc -c -mcpu=cortex-a8 main.c as -mcpu=cortex-a8 -o functions.o functions.s gcc -o main.o functions.o functions.o: In function `_start': (.text+0x0): multiple definition of `_start' /usr/lib/gcc/arm-linux-gnueabi/4.3.3/../../../crt1.o:init.c:(.text+0x0): first defined here /usr/lib/gcc/arm-linux-gnueabi/4.3.3/../../../crt1.o: In function `_start': init.c:(.text+0x30): undefined reference to `main' collect2: ld returned 1 exit status make: *** [hello] Error 1

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  • Program execution stop at scanf???

    - by Mohit Deshpande
    main.c (with all the headers like stdio, stdlib, etc): int main() { int input; while(1) { printf("\n"); printf("\n1. Add new node"); printf("\n2. Delete existing node"); printf("\n3. Print all data"); printf("\n4. Exit"); printf("Enter your option -> "); scanf("%d", &input); string key = ""; string tempKey = ""; string tempValue = ""; Node newNode; Node temp; switch (input) { case 1: printf("\nEnter a key: "); scanf("%s", tempKey); printf("\nEnter a value: "); scanf("%s", tempValue); //execution ternimates here newNode.key = tempKey; newNode.value = tempValue; AddNode(newNode); break; case 2: printf("\nEnter the key of the node: "); scanf("%s", key); temp = GetNode(key); DeleteNode(temp); break; case 3: printf("\n"); PrintAllNodes(); break; case 4: exit(0); break; default: printf("\nWrong option chosen!\n"); break; } } return 0; } storage.h: #ifndef DATABASEIO_H_ #define DATABASEIO_H_ //typedefs typedef char *string; /* * main struct with key, value, * and pointer to next struct * Also typedefs Node and NodePtr */ typedef struct Node { string key; string value; struct Node *next; } Node, *NodePtr; //Function Prototypes void AddNode(Node node); void DeleteNode(Node node); Node GetNode(string key); void PrintAllNodes(); #endif /* DATABASEIO_H_ */ I am using Eclipse CDT, and when I enter 1, then I enter a key. Then the console says . I used gdb and got this error: Program received signal SIGSEGV, Segmentation fault. 0x00177024 in _IO_vfscanf () from /lib/tls/i686/cmov/libc.so.6 Any ideas why?

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  • Why does my C++ LinkedList cause a EXC_BAD_ACCESS?

    - by Anthony Glyadchenko
    When I call the cmremoveNode method in my LinkedList from outside code, I get an EXC_BAD_ACCESS. /* * LinkedList.h * Lab 6 * * Created by Anthony Glyadchenko on 3/22/10. * Copyright 2010 __MyCompanyName__. All rights reserved. * */ #include <stdio.h> #include <iostream> #include <fstream> #include <iomanip> using namespace std; class ctNode { friend class ctlinkList ; // friend class allowed to access private data private: string sfileWord ; // used to allocate and store input word int iwordCnt ; // number of word occurrances ctNode* ctpnext ; // point of Type Node, points to next link list element }; class ctlinkList { private: ctNode* ctphead ; // initialized by constructor public: ctlinkList () { ctphead = NULL ; } ctNode* gethead () { return ctphead ; } string cminsertNode (string svalue) { ctNode* ctptmpHead = ctphead ; if ( ctphead == NULL ) { // allocate new and set head ctptmpHead = ctphead = new ctNode ; ctphead -> ctpnext = NULL ; ctphead -> sfileWord = svalue ; } else { //find last ctnode do { if ( ctptmpHead -> ctpnext != NULL ) ctptmpHead = ctptmpHead -> ctpnext ; } while ( ctptmpHead -> ctpnext != NULL ) ; // fall thru found last node ctptmpHead -> ctpnext = new ctNode ; ctptmpHead = ctptmpHead -> ctpnext ; ctptmpHead -> ctpnext = NULL ; ctptmpHead -> sfileWord = svalue ; } return ctptmpHead -> sfileWord ; } string cmreturnNode (string svalue) { return NULL; } string cmremoveNode (string svalue) { if (ctphead == NULL) return NULL; ctNode *tmpHead = ctphead; while (tmpHead->sfileWord != svalue || tmpHead->ctpnext != NULL){ tmpHead = tmpHead->ctpnext; } if (tmpHead == NULL){ return NULL; } else { while (tmpHead != NULL){ tmpHead = tmpHead->ctpnext; } } return tmpHead->sfileWord; } string cmlistList () { string tempList; ctNode *tmpHead = ctphead; if (ctphead == NULL){ return NULL; } else{ while (tmpHead != NULL){ cout << tmpHead->sfileWord << " "; tempList += tmpHead->sfileWord; tmpHead = tmpHead -> ctpnext; } } return tempList; } }; Why is this happening?

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  • 23warning: assignment makes pointer from integer without a cast

    - by FILIaS
    Im new in programming c with arrays and files. Im just trying to run the following code but i get warnings like that: 23 44 warning: assignment makes pointer from integer without a cast Any help? It might be silly... but I cant find what's wrong. #include<stdio.h> FILE *fp; FILE *cw; char filename_game[40],filename_words[40]; int main() { while(1) { /* Input filenames. */ printf("\n Enter the name of the file with the cryptwords array: \n"); gets(filename_game); printf("\n Give the name of the file with crypted words:\n"); gets(filename_words); /* Try to open the file with the game */ if (fp=fopen("crypt.txt","r")!=NULL) //line23 { printf("\n Successful opening %s \n",filename_game); fclose(fp); puts("\n Enter x to exit,any other to continue! \n "); if ( (getc(stdin))=='x') break; else continue; } else { fprintf(stderr,"ERROR!%s \n",filename_game); puts("\n Enter x to exit,any other to continue! \n"); if (getc(stdin)=='x') break; else continue; } /* Try to open the file with the names. */ if (cw=fopen("words.txt","r")!=NULL) //line 44 { printf("\n Successful opening %s \n",filename_words); fclose(cw); puts("\n Enter x to exit,any other to continue \n "); if ( (getc(stdin))=='x') break; else continue; } else { fprintf(stderr,"ERROR!%s \n",filename_words); puts("\n Enter x to exit,any other to continue! \n"); if (getc(stdin)=='x') break; else continue; } } return 0; }

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  • Structs, strtok, segmentation fault

    - by FILIaS
    I'm trying to make a programme with structs and files.The following is just a part of my code(it;s not all). What i'm trying to do is: ask the user to write his command. eg. delete John eg. enter John James 5000 ipad purchase. The problem is that I want to split the command in order to save its 'args' for a struct element. That's why i used strtok. BUT I'm facing another problem in who to 'put' these on the struct. #include <stdio.h> #include <stdlib.h> #include <string.h> #define MAX 100 char command[1500]; struct catalogue { char short_name[50]; char surname[50]; signed int amount; char description[1000]; }*catalog[MAX]; int main ( int argc, char *argv[] ) { int i,n; char choice[3]; printf(">sort1: Print savings sorted by surname\n"); printf(">sort2: Print savings sorted by amount\n"); printf(">search+name:Print savings of each name searched\n"); printf(">delete+full_name+amount: Erase saving\n"); printf(">enter+full_name+amount+description: Enter saving \n"); printf(">quit: Update + EXIT program.\n"); printf("Choose your selection:\n>"); gets(command); //it save the whole command /*in choice it;s saved only the first 2 letters(needed for menu choice again)*/ strncpy(choice,command,2); choice[2]='\0'; char** args = (char**)malloc(strlen(command)*sizeof(char*)); memset(args, 0, sizeof(char*)*strlen(command)); char* curToken = strtok(command, " \t"); for (n = 0; curToken != NULL; ++n) { args[n] = strdup(curToken); curToken = strtok(NULL, " \t"); *catalog[n]->short_name=*args[1]; *catalog[n]->surname=args[2]; catalog[n]->amount=atoi(args[3]); *catalog[n]->description=args[4]; } return 0; } I get a warning (warning: assignment makes integer from pointer without a cast) for the lines: *catalog[n]->short_name=*args[1]; *catalog[n]->surname=args[2]; *catalog[n]->description=args[4]; As a result, after running the program i get a Segmentation Fault... Any help? Any ideas?

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  • Finite State Machine Spellchecker

    - by Durell
    I would love to have a debugged copy of the finite state machine code below. I tried debugging but could not, all the machine has to do is to spell check the word "and",an equivalent program using case is welcomed. #include<cstdlib> #include<stdio.h> #include<string.h> #include<iostream> #include<string> using namespace std; char in_str; int n; void spell_check() { char data[256]; int i; FILE *in_file; in_file=fopen("C:\\Users\\mytorinna\\Desktop\\a.txt","r+"); while (!feof(in_file)) { for(i=0;i<256;i++) { fscanf(in_file,"%c",in_str); data[i]=in_str; } //n = strlen(in_str); //start(data); cout<<data; } } void start(char data) { // char next_char; //int i = 0; // for(i=0;i<256;i++) // if (n == 0) { if(data[i]="a") { state_A(); exit; } else { cout<<"I am comming"; } // cout<<"This is an empty string"; // exit();//do something here to terminate the program } } void state_A(int i) { if(in_str[i] == 'n') { i++; if(i<n) state_AN(i); else error(); } else error(); } void state_AN(int i) { if(in_str[i] == 'd') { if(i == n-1) cout<<" Your keyword spelling is correct"; else cout<<"Wrong keyword spelling"; } } int main() { spell_check(); system("pause"); return 0; }

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  • parent process, and a child process..

    - by icelated
    I am trying to write a program that The parent process will take the arguments to main() and send the characters in them one at a time to the child process through a pipe (one call to write for each character). The child process will count the characters sent to it by the parent process and print out the number of characters it received from the parent. The child process should not use the arguments to main() in any way whatsoever. The child should return normally and not have the parent kill the child. Am i counting the arguments right? am i sending the arguments in one at a time, and am i reaping the child? #include <sys/wait.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <string.h> #define size = 100; int main(int argc, char *argv[]) { int i, count =0; int c; int fdest[2]; // for pipe pid_t pid; //process IDs char buffer[BUFSIZ]; if (pipe(fdest) < 0) /* attempt to create pipe */ perror( "pipe" ); if ((pid = fork()) < 0) /* attempt to create child / parent process */ { perror( "fork" ); } /* parent process */ else if (pid > 0) { close(fdest[0]); for (i=1; i < argc; ++i) { for (c=0; c < strlen(argv[i]); ++c) { write(fdest[1], &argv[i][c], 1); } } close(fdest[1]); wait(NULL); exit(0); } else { /* child Process */ close(fdest[1]); while (read(fdest[0], &buffer, 1) > 0) { count++; } printf("\nchild: counted %d characters\n", count); } wait(NULL); exit(0); }

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  • Problem compiling c++ in CodeGear

    - by Carlos
    I have written a C++ program for a University assignment. I used Netbeans 6.8 running on my Mac and the code runs smoothly, no warnings, errors or problems/bugs. However when compiling and running on a Windows computer using CodeGear RAD Studio 2009 (C++ Builder) am getting several errors. [BCC32 Error] main.cpp(51): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(62): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(67): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(112): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(121): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(130): E2093 'operator==' not implemented in type 'string' for arguments of the same type [BCC32 Error] main.cpp(133): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(139): E2094 'operator<<' not implemented in type 'ostream' for arguments of type 'string' [BCC32 Error] main.cpp(153): E2094 'operator<<' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(199): E2094 'operator>>' not implemented in type 'fstream' for arguments of type 'string' [BCC32 Error] main.cpp(219): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(231): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(240): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(262): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' [BCC32 Error] main.cpp(264): E2094 'operator>>' not implemented in type 'istream' for arguments of type 'string' These are the header files am using #include <iostream> #include <fstream> #include <cmath> #include <stdio> #include <windows> //I added this one just to check and still does not work (I didnt have it on Netbeans/Mac) using namespace std; Any ideas what is producing the errors and how can I fix it?

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  • CUDA, more threads for same work = Longer run time despite better occupancy, Why?

    - by zenna
    I encountered a strange problem where increasing my occupancy by increasing the number of threads reduced performance. I created the following program to illustrate the problem: #include <stdio.h> #include <stdlib.h> #include <cuda_runtime.h> __global__ void less_threads(float * d_out) { int num_inliers; for (int j=0;j<800;++j) { //Do 12 computations num_inliers += threadIdx.x*1; num_inliers += threadIdx.x*2; num_inliers += threadIdx.x*3; num_inliers += threadIdx.x*4; num_inliers += threadIdx.x*5; num_inliers += threadIdx.x*6; num_inliers += threadIdx.x*7; num_inliers += threadIdx.x*8; num_inliers += threadIdx.x*9; num_inliers += threadIdx.x*10; num_inliers += threadIdx.x*11; num_inliers += threadIdx.x*12; } if (threadIdx.x == -1) d_out[blockIdx.x*blockDim.x+threadIdx.x] = num_inliers; } __global__ void more_threads(float *d_out) { int num_inliers; for (int j=0;j<800;++j) { // Do 4 computations num_inliers += threadIdx.x*1; num_inliers += threadIdx.x*2; num_inliers += threadIdx.x*3; num_inliers += threadIdx.x*4; } if (threadIdx.x == -1) d_out[blockIdx.x*blockDim.x+threadIdx.x] = num_inliers; } int main(int argc, char* argv[]) { float *d_out = NULL; cudaMalloc((void**)&d_out,sizeof(float)*25000); more_threads<<<780,128>>>(d_out); less_threads<<<780,32>>>(d_out); return 0; } Note both kernels should do the same amount of work in total, the (if threadIdx.x == -1 is a trick to stop the compiler optimising everything out and leaving an empty kernel). The work should be the same as more_threads is using 4 times as many threads but with each thread doing 4 times less work. Significant results form the profiler results are as followsL: more_threads: GPU runtime = 1474 us,reg per thread = 6,occupancy=1,branch=83746,divergent_branch = 26,instructions = 584065,gst request=1084552 less_threads: GPU runtime = 921 us,reg per thread = 14,occupancy=0.25,branch=20956,divergent_branch = 26,instructions = 312663,gst request=677381 As I said previously, the run time of the kernel using more threads is longer, this could be due to the increased number of instructions. Why are there more instructions? Why is there any branching, let alone divergent branching, considering there is no conditional code? Why are there any gst requests when there is no global memory access? What is going on here! Thanks

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  • Counting Alphabetic Characters That Are Contained in an Array with C

    - by Craig
    Hello everyone, I am having trouble with a homework question that I've been working at for quite some time. I don't know exactly why the question is asking and need some clarification on that and also a push in the right direction. Here is the question: (2) Solve this problem using one single subscripted array of counters. The program uses an array of characters defined using the C initialization feature. The program counts the number of each of the alphabetic characters a to z (only lower case characters are counted) and prints a report (in a neat table) of the number of occurrences of each lower case character found. Only print the counts for the letters that occur at least once. That is do not print a count if it is zero. DO NOT use a switch statement in your solution. NOTE: if x is of type char, x-‘a’ is the difference between the ASCII codes for the character in x and the character ‘a’. For example if x holds the character ‘c’ then x-‘a’ has the value 2, while if x holds the character ‘d’, then x-‘a’ has the value 3. Provide test results using the following string: “This is an example of text for exercise (2).” And here is my source code so far: #include<stdio.h> int main() { char c[] = "This is an example of text for exercise (2)."; char d[26]; int i; int j = 0; int k; j = 0; //char s = 97; for(i = 0; i < sizeof(c); i++) { for(s = 'a'; s < 'z'; s++){ if( c[i] == s){ k++; printf("%c,%d\n", s, k); k = 0; } } } return 0; } As you can see, my current solution is a little anemic. Thanks for the help, and I know everyone on the net doesn't necessarily like helping with other people's homework. ;P

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  • Help making this code run faster for spoj.

    - by Josh Meredith
    I've been doing a few of the challenges on the Sphere Online Judge, but I can't seem to get the second problem (the prime generator) to run within the time limit. Does anyone have any tips for increasing the speed of the following code? #include <stdio.h> #include <math.h> int is_prime(int n); void make_sieve(); void fast_prime(int n); int primes[16000]; int main() { int nlines; int m, n; make_sieve(); scanf("%d", &nlines); for (; nlines >= 1; nlines--) { scanf("%d %d", &m, &n); if (!(m % 2)) { m++; } for ( ; m < n; m+=2) { fast_prime(m); } printf("\n"); } return 0; } /* Prints a number if it's prime. */ inline void fast_prime(int n) { int j; for (int i = 0; ((j = primes[i]) > -1); i++) { if (!(n % j)) { return; } } printf("%d\n", n); } /* Create an array listing prime numbers. */ void make_sieve() { int j = 0; for (int i = 0; i < 16000; i++) { primes[i] = -1; } for (int i = 2; i < 32000; i++) { if (i % 2) { if (is_prime(i)) { primes[j] = i; j++; } } } return; } /* Test if a number is prime. Return 1 if prime. Return 0 if not. */ int is_prime(int n) { int rootofn; rootofn = sqrt(n); if ((n <= 2) || (n == 3) || (n == 5) || (n == 7)) { return 1; } if (((n % 2) == 0) || ((n % 3) == 0) || ((n % 5) == 0) || ((n % 7) == 0)) { return 0; } for (int i = 11; i < rootofn; i += 2) { if ((n % i) == 0) { return 0; } } return 1; }

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  • realloc - converting int to char

    - by Mike
    I'm converting an array of integers into a char by iterating through the whole array, and then I'm adding the resulting string to ncurses's method new_item. For some reason I'm doing something wrong the way I reallocate memory, thus I get the the first column as: -4 Choice 1 0 Choice 1 4 Choice 2 1 Choice 1 4 Choice 3 - Instead of - 2 Choice 1 4 Choice 4 3 Choice 1 4 Exit 4 Choice 1 - #include <stdio.h> #include <stdlib.h> #include <curses.h> #include <menu.h> #define ARRAY_SIZE(a) (sizeof(a) / sizeof(a[0])) #define CTRLD 4 char *choices[] = { "Choice 1", "Choice 2", "Choice 3", "Choice 4", "Exit", }; int table[5]={0,1,2,3,4}; int main() { ITEM **my_items; int c; MENU *my_menu; int n_choices, i; ITEM *cur_item; initscr(); cbreak(); noecho(); keypad(stdscr, TRUE); n_choices = ARRAY_SIZE(choices); my_items = (ITEM **)calloc(n_choices + 1, sizeof(ITEM *)); // right here char *convert = NULL; for(i = 0; i < n_choices; ++i){ convert = (char *) realloc (convert, sizeof(char) * 4); sprintf(convert, "%i", table[i]); my_items[i] = new_item(convert, choices[i]); } my_items[n_choices] = (ITEM *)NULL; my_menu = new_menu((ITEM **)my_items); mvprintw(LINES - 2, 0, "F1 to Exit"); post_menu(my_menu); refresh(); while((c = getch()) != KEY_F(1)) { switch(c) { case KEY_DOWN: menu_driver(my_menu, REQ_DOWN_ITEM); break; case KEY_UP: menu_driver(my_menu, REQ_UP_ITEM); break; } } free(convert); unpost_menu(my_menu); free_item(my_items[0]); free_item(my_items[1]); free_item(my_items[2]); free_item(my_items[3]); free_item(my_items[4]); free_menu(my_menu); endwin(); }

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  • What is `objc_msgSend_fixup`, exactly?

    - by Luis Antonio Botelho O. Leite
    I'm messing around with the Objective-C runtime, trying to compile objective-c code without linking it against libobjc, and I'm having some segmentation fault problems with a program, so I generated an assembly file from it. I think it's not necessary to show the whole assembly file. At some point of my main function, I've got the following line (which, by the way, is the line after which I get the seg fault): callq *l_objc_msgSend_fixup_alloc and here is the definition for l_objc_msgSend_fixup_alloc: .hidden l_objc_msgSend_fixup_alloc # @"\01l_objc_msgSend_fixup_alloc" .type l_objc_msgSend_fixup_alloc,@object .section "__DATA, __objc_msgrefs, coalesced","aw",@progbits .weak l_objc_msgSend_fixup_alloc .align 16 l_objc_msgSend_fixup_alloc: .quad objc_msgSend_fixup .quad L_OBJC_METH_VAR_NAME_ .size l_objc_msgSend_fixup_alloc, 16 I've reimplemented objc_msgSend_fixup as a function (id objc_msgSend_fixup(id self, SEL op, ...)) which returns nil (just to see what happens), but this function isn't even being called (the program crashes before calling it). So, my question is, what is callq *l_objc_msgSend_fixup_alloc supposed to do and what is objc_msgSend_fixup (after l_objc_msgSend_fixup_alloc:) supposed to be (a function or an object)? Edit To better explain, I'm not linking my source file against the objc library. What I'm trying to do is implement some parts of the libray, just to see how it works. Here is an approach of what I've done: #include <stdio.h> #include <objc/runtime.h> @interface MyClass { } +(id) alloc; @end @implementation MyClass +(id) alloc { // alloc the object return nil; } @end id objc_msgSend_fixup(id self, SEL op, ...) { printf("Calling objc_msgSend_fixup()...\n"); // looks for the method implementation for SEL in self's vtable return nil; // Since this is just a test, this function doesn't need to do that } int main(int argc, char *argv[]) { MyClass *m; m = [MyClass alloc]; // At this point, according to the assembly code generated // objc_msgSend_fixup should be called. So, the program should, at least, print // "Calling objc_msgSend_fixup()..." on the screen, but it crashes before // objc_msgSend_fixup() is called... return 0; } If the runtime needs to access the object's vtable to find the correct method to call, what is the function which actually does this? I think it is objc_msgSend_fixup, in this case. So, when objc_msgSend_fixup is called, it receives an object as one of its parameters, and, if this object hasn't been initialized, the function fails. So, I've implemented my own version of objc_msgSend_fixup. According to the assembly source above, it should be called. It doesn't matter if the function is actually looking for the implementation of the selector passed as parameter. I just want objc_msgSend_lookup to be called. But, it's not being called, that is, the function that looks for the object's data is not even being called, instead of being called and cause a fault (because it returns a nil (which, by the way, doesn't matter)). The program seg fails before objc_msgSend_lookup is called...

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  • Unintentional concatenation in Bison/Yacc grammar.

    - by troutwine
    I am experimenting with lex and yacc and have run into a strange issue, but I think it would be best to show you my code before detailing the issue. This is my lexer: %{ #include <stdlib.h> #include <string.h> #include "y.tab.h" void yyerror(char *); %} %% [a-zA-Z]+ { yylval.strV = yytext; return ID; } [0-9]+ { yylval.intV = atoi(yytext); return INTEGER; } [\n] { return *yytext; } [ \t] ; . yyerror("invalid character"); %% int yywrap(void) { return 1; } This is my parser: %{ #include <stdio.h> int yydebug=1; void prompt(); void yyerror(char *); int yylex(void); %} %union { int intV; char *strV; } %token INTEGER ID %% program: program statement EOF { prompt(); } | program EOF { prompt(); } | { prompt(); } ; args: /* empty */ | args ID { printf(":%s ", $<strV>2); } ; statement: ID args { printf("%s", $<strV>1); } | INTEGER { printf("%d", $<intV>1); } ; EOF: '\n' %% void yyerror(char *s) { fprintf(stderr, "%s\n", s); } void prompt() { printf("> "); } int main(void) { yyparse(); return 0; } A very simple language, consisting of no more than strings and integer and a basic REPL. Now, you'll note in the parser that args are output with a leading colon, the intention being that, when combined with the first pattern of the rule of the statement the interaction with the REPL would look something like this: > aaa aa a :aa :a aaa> However, the interaction is this: > aaa aa a :aa :a aaa aa aa > Why does the token ID in the following rule statement: ID args { printf("%s", $<strV>1); } | INTEGER { printf("%d", $<intV>1); } ; have the semantic value of the total input string, newline included? How can my grammar be reworked so that the interaction I intended?

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  • Unexpected output from Bubblesort program with MSVC vs TCC

    - by Sujith S Pillai
    One of my friends sent this code to me, saying it doesn't work as expected: #include<stdio.h> void main() { int a [10] ={23, 100, 20, 30, 25, 45, 40, 55, 43, 42}; int sizeOfInput = sizeof(a)/sizeof(int); int b, outer, inner, c; printf("Size is : %d \n", sizeOfInput); printf("Values before bubble sort are : \n"); for ( b = 0; b &lt; sizeOfInput; b++) printf("%d\n", a[b]); printf("End of values before bubble sort... \n"); for ( outer = sizeOfInput; outer &gt; 0; outer-- ) { for ( inner = 0 ; inner &lt; outer ; inner++) { printf ( "Comparing positions: %d and %d\n",inner,inner+1); if ( a[inner] &gt; a[inner + 1] ) { int tmp = a[inner]; a[inner] = a [inner+1]; a[inner+1] = tmp; } } printf ( "Bubble sort total array size after inner loop is %d :\n",sizeOfInput); printf ( "Bubble sort sizeOfInput after inner loop is %d :\n",sizeOfInput); } printf ( "Bubble sort total array size at the end is %d :\n",sizeOfInput); for ( c = 0 ; c &lt; sizeOfInput; c++) printf("Element: %d\n", a[c]); } I am using Micosoft Visual Studio Command Line Tool for compiling this on a Windows XP machine. cl /EHsc bubblesort01.c My friend gets the correct output on a dinosaur machine (code is compiled using TCC there). My output is unexpected. The array mysteriously grows in size, in between. If you change the code so that the variable sizeOfInput is changed to sizeOfInputt, it gives the expected results! A search done at Microsoft Visual C++ Developer Center doesn't give any results for "sizeOfInput". I am not a C/C++ expert, and am curious to find out why this happens - any C/C++ experts who can "shed some light" on this? Unrelated note: I seriously thought of rewriting the whole code to use quicksort or merge sort before posting it here. But, after all, it is not Stooge sort... Edit: I know the code is not correct (it reads beyond the last element), but I am curious why the variable name makes a difference.

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  • Help me understand this "Programming pearls" bitsort program

    - by ardsrk
    Jon Bentley in Column 1 of his book programming pearls introduces a technique for sorting a sequence of non-zero positive integers using bit vectors. I have taken the program bitsort.c from here and pasted it below: /* Copyright (C) 1999 Lucent Technologies */ /* From 'Programming Pearls' by Jon Bentley */ /* bitsort.c -- bitmap sort from Column 1 * Sort distinct integers in the range [0..N-1] */ #include <stdio.h> #define BITSPERWORD 32 #define SHIFT 5 #define MASK 0x1F #define N 10000000 int a[1 + N/BITSPERWORD]; void set(int i) { int sh = i>>SHIFT; a[i>>SHIFT] |= (1<<(i & MASK)); } void clr(int i) { a[i>>SHIFT] &= ~(1<<(i & MASK)); } int test(int i){ return a[i>>SHIFT] & (1<<(i & MASK)); } int main() { int i; for (i = 0; i < N; i++) clr(i); /*Replace above 2 lines with below 3 for word-parallel init int top = 1 + N/BITSPERWORD; for (i = 0; i < top; i++) a[i] = 0; */ while (scanf("%d", &i) != EOF) set(i); for (i = 0; i < N; i++) if (test(i)) printf("%d\n", i); return 0; } I understand what the functions clr, set and test are doing and explain them below: ( please correct me if I am wrong here ). clr clears the ith bit set sets the ith bit test returns the value at the ith bit Now, I don't understand how the functions do what they do. I am unable to figure out all the bit manipulation happening in those three functions. Please help.

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