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awk replace first line of files

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# 1  
Old 10-15-2011
awk replace first line of files
Hi,

I am very new to scripting and I know this is a very basic question, but I couldnt find a solution online or make it work.
I need to search all my directories and subdirectories for files named run_* and replace the first line if some pattern is found.
Here is my first attempt, which almost works:
Code:
find -name "run_*" -exec awk '{if($0 == "#/bin/ksh" || $0 == "#/bin/bash/") print "#\!/bin/bash"; else print $0}' '{}' > "{}_nnew" \;  -exec mv  "{}_nnew" "{}" \;


My problem is that I can not make awk recognize that {} has a value in the output (although it does for the input).
Any suggestions?
Last edited by Franklin52; 10-16-2011 at 08:07 AM.. Reason: Please use code tags for data and code samples, thank you
# 2  
Old 10-15-2011
Hi andlessa,

It would be useful if you say what you try to achieve. Next instruction saves original files with suffix .orig. Test it:
Code:
$ find . -type f -iname "run_*" -exec sed -i.orig -e '1 s|^#/bin/[a-zA-Z]\{1,2\}sh|#!/bin/bash|' {} \;

Regards,
Birei
# 3  
Old 10-15-2011

Don't try to squeeze an entire script into the -exec command of find.

Pipe the output of find into a script which you can modify more easily:
Code:
pattern=something
newstring=whatever

find ... |
 while IFS= read -r file
 do
   {
     IFS= read -r line
     case $line in
       $pattern) {
                   printf "%s\n" "$newstring"
                   cat
                 } > tempfile && mv tempfile "$file"
                 ;;
     esac
   } < $file
 done

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