feat(unitproc/palign.sh):Add script to align path lists

[BK-2020-03.git] / unitproc / bkt-get_parent_dirnames

#!/usr/bin/env bash
# Desc: Provides newline-delimited list of each parent dir

yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
try() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
get_parent_dirnames() {
    # Desc: Provides newline-delimited list of each parent dir of a file or dir
    # Usage: get_parent_dirnames arg1
    # Input: arg1  input  path
    # Output: stdout   newline-delimited list of parent dirs
    # Version: 0.0.1
    # Depends: yell(), die(), try()
    local path

    # Check input
    if [[ $# -ne 1 ]]; then die "FATAL:Incorrect number of arguments:$#"; fi;
    if ! { [[ -f $1 ]] || [[ -d $1 ]]; }; then die "FATAL:Not a file or dir:$1"; fi;

    # Process path
    path="$1";
    while [[ -f $path ]] || [[ -d $path ]]; do
        path="$(dirname "$path")";
        name_base_previous="$name_base";
        name_base="$(basename "$path")";
        ## Check for stop condition (dirname returns same result as previous iteration)
        if [[ $name_base == "$name_base_previous" ]]; then break; fi;
        echo "$name_base";
    done;    
}; # Output parent dirnames to stdout

# Test code
sleep 1 && get_parent_dirnames /home/baltakatei/Downloads/ & # should work
sleep 2 && get_parent_dirnames /home/baltakatei/Downloads/ foo & # should fail
sleep 3 && get_parent_dirnames bar/baz & # should fail
sleep 4;