Script to change first line of files in directory Post: 302653619

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Top Forums Shell Programming and Scripting Script to change first line of files in directory Post 302653619 by agama on Saturday 9th of June 2012 03:31:48 PM

06-09-2012

Registered User

You only need the cd command in the if statement. Your directory is a relative path (doesn't start with a slant) and that is why it's erroring (there isn't a ./xxxx directory inside of the directory which you switched to earlier in the script.

You also are wasting effort copying the file back in your script (extra i/o adds to the latency).

Code:

#!/usr/bin/bash

# mol_filename2firstline_2.sh 
### unneeded cd "$1"

if ! cd "${1:-no-such-directory}"     # also quote on the off chance that something in the path has spaces
then
   echo "abort: could not switch to '$1' or parameter was missing"
   exit 1
fi

ls | while read f              # for *   doesn't handle filenames with spaces or large numbers of files. 
do
    [ ! -f "$f" ] && continue

    printf %s\\n "$f" >"$f.new"
    if ! sed '1d' "$f" >>"$f.new"
    then
        rm "$f.new"
    else
        mv "$f.new" "$f"
    fi
done

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