Small Self-Extracting Archiver

sself

#!/bin/sh

# Name    : sself
# Created : 2011-10-09
# Author  : cwilper
# Purpose : Creates a self-extracting archive (a shell script containing a
#           compressed tar file) out of the content of a given directory. When
#           executed, the archive will be expanded into /tmp/sself/ (which will
#           be cleared first if it already exists), and if a "run" script exists
#           in the root of the archive, it will be executed. Standard output and
#           standard error will be output to /tmp/sself/run.log. This is similar
#           to the more feature-rich makeself[1], but is designed to add as little
#           overhead as possible to the archive.
# Usage   : sself INPUT_DIR OUTPUT_FILE
# Example : sself /path/to/input-dir my-archive.sh
# Related : [1] https://github.com/megastep/makeself

if [[ ! "$2" ]]; then
    echo "Usage: $0 INPUT_DIR OUTPUT_FILE"
    exit 1
fi
echo "#!/bin/sh" > $2
echo "m=\$(grep -a -n '^F:$' \$0|cut -d ':' -f 1)" >> $2
echo "s=\$((m + 1))" >> $2
echo "d=/tmp/sself" >> $2
echo "rm -rf \$d" >> $2
echo "mkdir \$d" >> $2
echo "tail -n +\$s \$0 | tar -x -z -C \$d -f -" >> $2
echo "if [ -f \$d/run ]; then" >> $2
echo "  pushd ." >> $2                                                             
echo "  cd \$d" >> $2                                                                        
echo "  ./run > run.log 2>&1" >> $2                                                             
echo "  popd" >> $2
echo "fi" >> $2
echo "exit 0" >> $2
echo "F:" >> $2
tar -c -C $1 . | gzip >> $2   
chmod 755 $2