Working with compressed files

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Revision as of 15:07, 23 November 2011 by Roux (talk | contribs)

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Linux usually provides a couple of command piping gzip

zgrep, zcat, zdiff, zless, zmore, zegrep,...

Here is a simple extension of tail and head for zipped files, that you can call ztail and zhead (example is for tail, replace "tail" with "head" everywhere to get zhead) and add to your own /bin directory:

#!/bin/bash
PATH=${GZIP_BINDIR-'/bin'}:$PATH

usage="Usage: $0 [OPTIONS]... [FILES]...
Like 'tail', but operate on the uncompressed contents of any compressed FILEs.

Options are the same as for 'tail'."

case $1 in
--help)    exec echo "$usage";;
-h)        exec echo "$usage";;
esac

options=""
files=""
for i in $@; do
str="$i"
if test -f $i && [ ${str:(-3)} = ".gz" ]; then
    files=$files"$i "
else
    if [ ${str:0:1} = "-" ] && [ $str != "-v" ] && [ $str != "--verbose" ]; then
        options=$options"$i "
    elif [ $str != "-v" ] && [ $str != "--verbose" ]; then
        echo -ne "***Warning: $i is neither a regular zip file or a regular option***\n\n"
    fi
fi
done

for file in $files; do
    echo "==>"$file"<=="
    exec gzip -cd $file | tail $options
done