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Full Discussion: head usage
Top Forums Shell Programming and Scripting head usage Post 302168260 by qneill on Sunday 17th of February 2008 09:50:04 PM
Old 02-17-2008
Quote:
Originally Posted by vasuarjula
$ct=1
head -n $ct file.
A good debugging technique in most shells is to use "-x" which prints each command as it is executed. I put your commands in a script named 'yourscript'
Code:
bash$ cat yourscript                          # see the script
$ct=1
head -n $ct file

and then execute with -x:
Code:
bash$ bash -x yourscript                  # execute the script with -x
+ =1                                      # notice '$ct' is blank (you want 'ct')
script: line 1: =1: command not found     # which causes problems
+ head -n file                            # '$ct' is again blank
head: file: invalid number of lines       # more problems

Here's your corrected script (using 'ct=1')
Code:
bash$ cat yourscript 
ct=1
head -n $ct file
bash$ cat file
blah blah one
blah blah two
bash$ bash -x yourscript 
+ ct=1
+ head -n 1 file
blah blah one

 

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LEARN ABOUT SUSE

git-cherry

GIT-CHERRY(1)							    Git Manual							     GIT-CHERRY(1)

NAME

       git-cherry - Find commits not merged upstream

SYNOPSIS

       git cherry [-v] [<upstream> [<head> [<limit>]]]

DESCRIPTION

       The changeset (or "diff") of each commit between the fork-point and <head> is compared against each commit between the fork-point and
       <upstream>. The commits are compared with their patch id, obtained from the git patch-id program.

       Every commit that doesn't exist in the <upstream> branch has its id (sha1) reported, prefixed by a symbol. The ones that have equivalent
       change already in the <upstream> branch are prefixed with a minus (-) sign, and those that only exist in the <head> branch are prefixed
       with a plus (+) symbol:

		      __*__*__*__*__> <upstream>
		     /
	   fork-point
		     \__+__+__-__+__+__-__+__> <head>

       If a <limit> has been given then the commits along the <head> branch up to and including <limit> are not reported:

		      __*__*__*__*__> <upstream>
		     /
	   fork-point
		     \__*__*__<limit>__-__+__> <head>

       Because git cherry compares the changeset rather than the commit id (sha1), you can use git cherry to find out if a commit you made locally
       has been applied <upstream> under a different commit id. For example, this will happen if you're feeding patches <upstream> via email
       rather than pushing or pulling commits directly.

OPTIONS

       -v
	   Verbose.

       <upstream>
	   Upstream branch to compare against. Defaults to the first tracked remote branch, if available.

       <head>
	   Working branch; defaults to HEAD.

       <limit>
	   Do not report commits up to (and including) limit.

SEE ALSO

       git-patch-id(1)

AUTHOR

       Written by Junio C Hamano <gitster@pobox.com[1]>

DOCUMENTATION

       Documentation by Junio C Hamano and the git-list <git@vger.kernel.org[2]>.

GIT

       Part of the git(1) suite

NOTES

	1. gitster@pobox.com
	   mailto:gitster@pobox.com

	2. git@vger.kernel.org
	   mailto:git@vger.kernel.org

Git 1.7.1							    07/05/2010							     GIT-CHERRY(1)
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