Assigning Git SHA1's without Git

Posted by git-noob on Stack Overflow See other posts from Stack Overflow or by git-noob
Published on 2009-02-16T08:53:23Z Indexed on 2010/04/01 1:13 UTC
Read the original article Hit count: 430

Filed under:

git

|

sha1

As I understand it when Git assigns a SHA1 hash to a file this SHA1 is unique to the file based on its contents.

As a result if a file moves from one repository to another the SHA1 for the file remains the same as its contents have not changed.

How does Git calculate the SHA1 digest? Does it do it on the full uncompressed file contents?

I would like to emulate assigning SHA1's outside of Git.

© Stack Overflow or respective owner

Related posts about git

git pull gives error: 401 Authorization Required while accessing https://git.foo.com/bar.git

as seen on Stack Overflow - Search for 'Stack Overflow'
My macbook pro is able to clone/push/pull from the company git server. My cent 6.3 vm gets a 401 error git clone https://git.acme.com/git/torque-setup "error: The requested URL returned error: 401 Authorization Required while accessing https://git.acme.com/git/torque-setup/info/refs As a work… >>> More
Can't install git on Ubuntu 12.10

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I'm following these instructions to install git on my laptop: http://git-scm.com/download/linux When I do: $ sudo apt-get install git-core This is what my terinal shows: Reading package lists... Done Building dependency tree Reading state information... Done The following packages… >>> More
Git apache : unable to push via http

as seen on Server Fault - Search for 'Server Fault'
I have to setup a server which can allow http vcs management (such as git and svn). svn support works well, but I have some trouble with git. Actual configuration: CentOS 5 Apache 2.2.8 Git 1.7.4.1 The /etc/httpd/conf/httpd.conf content: ServerTokens OS ServerRoot "/etc/httpd" PidFile run/httpd… >>> More
git on HTTP with gitolite and nginx

as seen on Server Fault - Search for 'Server Fault'
I am trying to setup a server where my git repo would be accessible with HTTP(S). I am using gitolite and nginx (and gitlab for web interface but I doubt it makes any difference). I have searched the whole afternoon and I think I'm stuck. I have think I have understood that nginx needs fcgiwrap… >>> More
Redmine git integration - issue in accessing git from redmine but not from external git client

as seen on Server Fault - Search for 'Server Fault'
I have setup redmine integration with apache as described in the redmine documentation. I have a /git path accessible with auth and /git-private accessible only to redmine. When I clone the repository through /git path, I get the up-to-date repo. But when I try to view it in redmine repo viewer, I… >>> More

Related posts about sha1

PBKDF2-HMAC-SHA1

as seen on Stack Overflow - Search for 'Stack Overflow'
To generate a valid pairwise master key for a WPA2 network a router uses the PBKDF2-HMAC-SHA1 algorithm. I understand that the sha1 function is performed 4096 times to derive the PMK, however I have two questions about the process. Excuse the pseudo code. 1) How is the input to the first instance… >>> More
Is it possible to get identical SHA1 hash?

as seen on Stack Overflow - Search for 'Stack Overflow'
Given two different strings S1 and S2 (S1 != S2) is it possible that: SHA1(S1) == SHA1(S2) is True? If yes - with what probability? Is there a upper bound on the length of a string, for which probably of getting duplicates is 0? If not - why not? Thanks >>> More
Is it possible to convert a 40-character SHA1 hash to a 20-character SHA1 hash?

as seen on Stack Overflow - Search for 'Stack Overflow'
My problem is a bit hairy, and I may be asking the wrong questions, so please bear with me... I have a legacy MySQL database which stores the user passwords & salts for a membership system. Both of these values have been hashed using the Ruby framework - roughly like this: hashedsalt = … >>> More
Is there any difference between md5 and sha1 in this situation?

as seen on Stack Overflow - Search for 'Stack Overflow'
It is known that 1. if ( md5(a) == md5(b) ) 2. then ( md5(a.z) == md5(b.z) ) 3. but ( md5(z.a) != md5(z.b) ) where the dots concatenate the strings. What happens in the second row if we change all the md5 to sha1? So: 1. if ( sha1(c) == sha1(d) ) 2. then ( sha1(c.z)… >>> More
iPhone: convert string using HMAC-SHA1

as seen on Stack Overflow - Search for 'Stack Overflow'
hi all, i want to generate HMAC-SHA1 of NSString type variable. I see the post but this method give me error in CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC); and NSString *hash = [HMAC base64Encoding]; line. Please suggest how can I generate the HMAC-SHA1 of any string… >>> More