shrug-show

#!/bin/dash

root_folder='.shrug'

if [ -z "$1" ]; then
    echo "usage: shrug-show <commit>:<filename>"
    exit 1
else 
    flag=`echo $1 | egrep ':'`
    if [ -z "$flag" ]; then
        # input invaild if does not contain colon
        echo "shrug-show: error: invalid object $1"
        exit 1
    else
    requested_commit_seq=`echo $1 | cut -d':' -f1`
    requested_filename=`echo $1 | cut -d':' -f2`
    fi

    if [ -z "$requested_commit_seq" ]; then
        # if no commit_seq then look for file in staged space
        # search current index using requested_filename for file real name(sha1sum-ed)
        requested_filename_sha1sum=`cat .shrug/.git/index | egrep " $requested_filename$" | cut -d' ' -f1`
        if [ -z "$requested_filename_sha1sum" ]; then
            echo "shrug-show: error: '$requested_filename' not found in index"
            exit 1
        else
            cat ".shrug/.git/objects/$requested_filename_sha1sum"
            exit 0
        fi
    else
        # check if requested_commit_seq ever exists
        commit_check_flag=`cat $root_folder/.git/COMMIT_EDITMSG | egrep "^$requested_commit_seq "`
        if [ -z "$commit_check_flag" ]; then
            echo "shrug-show: error: unknown commit '$requested_commit_seq'"
            exit 1
        else
            # invaild file if requested_commit_seq exists but no request_filename input
            if [ -z "$requested_filename" ]; then
                echo "shrug-show: error: invalid filename ''"
            else
                # search current index using requested_filename for file real name(sha1sum-ed)
                requested_filename_sha1sum=`cat .shrug/.git//objects/pack/pack-$requested_commit_seq.idx | egrep " $requested_filename$" | cut -d' ' -f1`
                if [ -z "$requested_filename_sha1sum" ]; then
                    echo "shrug-show: error: '$requested_filename' not found in commit $requested_commit_seq"
                    exit 1
                else
                    cat "$root_folder/.git/objects/pack/pack-$requested_commit_seq.pack/$requested_filename_sha1sum"
                    exit 0
                fi
            fi
        fi
    fi
fi