girt-show

#!/bin/dash

# if the .girt does not exit, output error message and exit
if ! test -d ".girt"
then
    echo "$0 : error: girt repository directory .girt not found" 1>&2
    exit 1
fi

# if the number of args is not equal to 1, output usage to stderr
if test "$#" -ne 1
then
    echo "usage: $0 <commit>:<filename>" 1>&2
    exit 1
fi


commit_num=$(echo "$1" | cut -d':' -f1) # firt part of the argument 
file_name=$(echo "$1" | cut -d':' -f2)  # second part of the argument

wrong_format=$(echo "$file_name" | grep -E '^[^a-zA-Z0-9]')

# if a file with valid name is provided output the error and exit 1
if test "$wrong_format" != ""
then
    echo "$0: error: invalid filename '$file_name'" 1>&2
    exit 1
fi

# if no commit number is provided
if test "$commit_num" = ""
then

    # go to the index and if the file exists, output its content
    if test -e ".girt/index/$file_name"
    then
        output=$(cat ".girt/index/$file_name")
        if test "$output" = ""
        then
            exit 0
        else
            echo "$output"
            exit 0
        fi

    # else output error message to stderr and exit 1
    else
        echo "$0: error: '$file_name' not found in index" 1>&2
        exit 1
    fi

# if the commit number is provided
else

    # get the valid commit numbers by running girt-log
    valid_commit=$(sh girt-log | cut -d' ' -f1)

    # by looping through the numbers from girt-log
    for valid_num in $valid_commit
    do
        # if the requested commit number is among the valids
        if test "$commit_num" -eq "$valid_num"
        then

            # if the requested file exist in the commit dir with the valid commit number
            if test -e ".girt/commit/$commit_num/$file_name"
            then

                # output the content of the file
                output=$(cat ".girt/commit/$commit_num/$file_name")
                echo "$output"
                exit 0

            # else the file does not exist in that commit 
            else
                echo "$0: error: '$file_name' not found in commit $commit_num" 1>&2
                exit 1
            fi
        else
            continue
        fi
    done
    echo "$0: error: unknown commit '$commit_num'" 1>&2
    exit 1
fi