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Top Forums Shell Programming and Scripting How to execute the rest of the code after commenting multiple lines? Post 302154818 by Yamini Thoppen on Wednesday 2nd of January 2008 02:09:33 AM
Old 01-02-2008
Thanks for your reply.

Quote:
Originally Posted by drl
Hi.

A few comments. First, there is a "quoted" string feature in the shells for HERE documents. The use prevents evaluation of everything up to the closing string, including unclosed quotes, variable issues, etc.

Second, ksh does a good job of diagnosing a missing, closing, matching HERE document string -- bash (2 & 3) simply stop.

A ksh example:
Code:
#!/usr/bin/env ksh

# @(#) s1       Demonstrate quick method to render code block inoperable.

set -o nounset
echo

debug=":"
debug="echo"

## The shebang using "env" line is designed for portability and
#  demonstrations. For higher security, use:
#
#  #!/bin/ksh -

## Use local command version for the commands in this demonstration.

echo "(Versions displayed with local utility \"version\")"
version >/dev/null 2>&1 && version ksh

echo
echo " Commands before commented-out block."

: <<'EOF'
garbage
junk
worthless
utterly without merit
" crud inside of double quotes "
' debris inside single quote '
" mess inside unmatched double-quotes
' detritus inside an unmatched single-quote pair
...
and so on.
EOF

echo
echo " Commands after  commented-out block."

echo
echo " Failed block quote due to unmatched HERE stings:"

echo
echo " Commands before commented-out block."

: <<'MISSING'
more junk
OOPS!

echo " Commands after  commented-out block."

exit 0

producing:
Code:
% ./s1

(Versions displayed with local utility "version")
pdksh 5.2.14 99/07/13.2

 Commands before commented-out block.

 Commands after  commented-out block.

 Failed block quote due to unmatched HERE stings:

 Commands before commented-out block.
./s1[53]: here document `MISSING' unclosed

I don't use ksh for reasons of availability (my shebangs almost always use simple "sh"), but in this case ksh is superior ... cheers, drl
Hi DRL,

Thanks for you explanation. But for me it is bit confusing, since i am not aware of the sh. i am using ksh only. Still i will try to understand this code.

Thanks
Yamini.
 

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GIT-STRIPSPACE(1)						    Git Manual							 GIT-STRIPSPACE(1)

NAME
git-stripspace - Remove unnecessary whitespace SYNOPSIS
git stripspace [-s | --strip-comments] git stripspace [-c | --comment-lines] DESCRIPTION
Read text, such as commit messages, notes, tags and branch descriptions, from the standard input and clean it in the manner used by Git. With no arguments, this will: o remove trailing whitespace from all lines o collapse multiple consecutive empty lines into one empty line o remove empty lines from the beginning and end of the input o add a missing to the last line if necessary. In the case where the input consists entirely of whitespace characters, no output will be produced. NOTE: This is intended for cleaning metadata, prefer the --whitespace=fix mode of git-apply(1) for correcting whitespace of patches or files in the repository. OPTIONS
-s, --strip-comments Skip and remove all lines starting with comment character (default #). -c, --comment-lines Prepend comment character and blank to each line. Lines will automatically be terminated with a newline. On empty lines, only the comment character will be prepended. EXAMPLES
Given the following noisy input with $ indicating the end of a line: |A brief introduction $ | $ |$ |A new paragraph$ |# with a commented-out line $ |explaining lots of stuff.$ |$ |# An old paragraph, also commented-out. $ | $ |The end.$ | $ Use git stripspace with no arguments to obtain: |A brief introduction$ |$ |A new paragraph$ |# with a commented-out line$ |explaining lots of stuff.$ |$ |# An old paragraph, also commented-out.$ |$ |The end.$ Use git stripspace --strip-comments to obtain: |A brief introduction$ |$ |A new paragraph$ |explaining lots of stuff.$ |$ |The end.$ GIT
Part of the git(1) suite Git 2.17.1 10/05/2018 GIT-STRIPSPACE(1)
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