confused about variables in bash

Posted by gappy on Super User See other posts from Super User or by gappy
Published on 2014-06-05T20:54:05Z Indexed on 2014/06/05 21:28 UTC
Read the original article Hit count: 346

Filed under:

bash

|

variables

I know that variables in bash have no type, but am confused about the value they are assigned.

The following simple script works fine in bash

#!/bin/bash 
tail -n +2 /cygdrive/c/workdir\ \(newco\,\ LLC\)/workfile.txt > \
/cygdrive/c/workdir\ \(newco\,\ LLC\)/workfile2.txt

However, the following does not

#!/bin/bash
tmpdir=/cygdrive/c/workdir\ \(newco\,\ LLC\)
tail -n +2 $tmpdir/workfile.txt > $tmpdir/workfile2.txt

Is there an explanation for this behavior?

© Super User or respective owner

Related posts about bash

launching a program from bash causes bash to go to new prompt

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
When I run a program from the console, e.g. me@box:~$ firefox I expect the console to log error messages (I think this is std out or std err?) and other items from the program, firefox in this case. But today I notice that bash just opens the program and goes to a new prompt, e.g. me@box:~$… >>> More
How to debug a .bash_profile

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Every command fails with "command not found" after changing .bash_profile?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Is there any fundamental difference between piping in mac and linux?

as seen on Super User - Search for 'Super User'
ps -e | grep bash sample output from a linux machine: 1128 pts/14 00:00:00 bash 7491 pts/7 00:00:00 bash 12651 pts/14 00:00:00 bash 16145 pts/2 00:00:00 bash sample output from a mac machine: 58352 ttys000 0:00.09 login -pfl username /bin/bash -c exec -la bash /bin/bash 58353 ttys000… >>> More
why is $0 set to -bash?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
First login process name seems to be set to "-bash", but if I subshell then it becomes "bash". for example: root@nowere:~# echo $0 -bash root@nowere:~# bash root@nowere:~# echo $0 bash -bash is causing some scripts to fail, such as . /usr/share/debconf/confmodule exec /usr/share/debconf/frontend… >>> More

Related posts about variables

System Expandable-String Environment Variables Can’t Reference User Environment Variables

as seen on Super User - Search for 'Super User'
Hi, I’ve run into a bit of a situation with Windows environment variables. I’ve narrowed it down to what may or may not makes sense and/or possibly be by design. It seems that expandable-string environment variables of the local machine cannot reference environment variables of the current user. For… >>> More
Local variables and instance variables

as seen on Stack Overflow - Search for 'Stack Overflow'
Why is it that instance variables are initialised to default values while local variables aren't? >>> More
Arguments, local variables, and global variables coding convention in Python

as seen on Stack Overflow - Search for 'Stack Overflow'
In python, there is no way to differentiate between arguments, local variables, and global variables. The easy way to do so might be have some coding convention such as Global variables start with _ and capital letter arguments end with with _ _Gvariable = 10 def hello(x_, y_): z = x_ + y_ Is… >>> More
Arguments, local variables, and global variables in Python

as seen on Stack Overflow - Search for 'Stack Overflow'
In python, there is no way to differentiate between arguments, local variables, and global variables. The easy way to do so might be have some coding convention such as Global variables start with _ and capital letter arguments end with with _ _Global variable = 10 def hello(x_, y_): z =… >>> More
Difference between putting variables in header vs putting variables in source

as seen on Stack Overflow - Search for 'Stack Overflow'
Say I declare a header file with a variable: int count; Then in the source file, I want to use count. Do I have to declare it as: extern int count Or can I just use it in my source file? All assuming that I have #include "someheader.h". Or should I just declare it in the source file? What is… >>> More