unitproc/palign.sh

   1 #!/bin/bash
   2 # Desc: Aligns path elements with spaces
   3 # Usage: palign.sh [path]
   4 #        find . -type f | palign.sh
   5 # Input: stdin   paths  newline-delimited paths (forward-slash delimited)
   6 #        psargs  paths  word-delimited paths (forward-slash delimited)
   7 # Output: stdout
   8 # Depends: Bash 5.1.16
   9 # Version: 0.0.1
  10
  11 yell() { echo "$0: $*" >&2; } # print script path and all args to stderr
  12 die() { yell "$*"; exit 111; } # same as yell() but non-zero exit status
  13 must() { "$@" || die "cannot $*"; } # runs args as command, reports args if command fails
  14 read_stdin() {
  15     # Desc: Consumes stdin; outputs as stdout lines
  16     # Input: stdin (consumes)
  17     # Output: stdout  (newline delimited)
  18     #         return  0  stdin read
  19     #         return  1  stdin not present
  20     # Example: printf "foo\nbar\n" | read_stdin
  21     # Depends: GNU bash (version 5.1.16), GNU Coreutils 8.32 (cat)
  22     # Version: 0.1.1
  23     # Attrib: Steven Baltakatei Sandoval (2024-01-29). reboil.com
  24     local input_stdin output;
  25
  26     # Store stdin
  27     if [[ -p /dev/stdin ]]; then
  28         input_stdin="$(cat -)" || {
  29             echo "FATAL:Error reading stdin." 1>&2; return 1; };
  30     else
  31         return 1;
  32     fi;
  33
  34     # Store as output array elements
  35     ## Read in stdin
  36     if [[ -n $input_stdin ]]; then
  37         while read -r line; do
  38             output+=("$line");
  39         done < <(printf "%s\n" "$input_stdin") || {
  40             echo "FATAL:Error parsing stdin."; return 1; };
  41     fi;
  42
  43     # Print to stdout
  44     printf "%s\n" "${output[@]}";
  45
  46     return 0;
  47 }; # read stdin to stdout lines
  48 read_psarg() {
  49     # Desc: Reads arguments; outputs as stdout lines
  50     # Input: args
  51     # Output: stdout (newline delimited)
  52     # Example: read_psarg "$@"
  53     # Depends: GNU bash (version 5.1.16)
  54     # Version: 0.0.1
  55     local input_psarg output;
  56
  57     # Store arguments
  58     if [[ $# -gt 0 ]]; then
  59         input_psarg="$*";
  60     fi;
  61
  62     # Store as output array elements
  63     ## Read in positional arguments
  64     if [[ -n $input_psarg ]]; then
  65         for arg in "$@"; do
  66             output+=("$arg");
  67         done;
  68     fi;
  69
  70     # Print to stdout
  71     printf "%s\n" "${output[@]}";
  72 }; # read positional argument to stdout lines
  73 calculate_max_lengths() {
  74     # Calculate maximum lengths of each hierarchical level
  75     # Input:   psargs  paths
  76     # Output:  stdout  ints  path element lengths (single line of space-separated ints)
  77     local -a paths=("$@");
  78     local lengths;
  79
  80     for path in "${paths[@]}"; do
  81         IFS='/' read -r -a parts <<< "$path";
  82         # Analyze path element lengths
  83         for i in "${!parts[@]}"; do
  84             # Save max path element lengths for previously analyzed paths
  85             #   Note: $(( condition ? value_true : value_false ))
  86             #     condition:  ${#parts[$i]} > ${lengths[$i]:-0}  is path element longer than previously seen corresponding paths?
  87             #     value_true: ${#parts[$i]}                      save new max length
  88             #     value_false ${lengths[$i]:-0}                  use previous value (or init with 0 if never seen before)
  89             lengths[$i]=$(( ${#parts[$i]} > ${lengths[$i]:-0} ? ${#parts[$i]} : ${lengths[$i]:-0} ));
  90         done;
  91     done;
  92     echo "${lengths[@]}";
  93 }; # Get maximum lengths of path elements as space-separated ints
  94 align_paths() {
  95     # Align paths
  96     # Input:  stdin
  97     # Output: stdout
  98     # Depends: calculate_max_lengths()
  99     local -a paths lengths;
 100
 101     # Read stdin
 102     while read -r line; do
 103         paths+=("$line");
 104     done < <(read_stdin);
 105
 106     IFS=" " read -r -a lengths <<< "$(calculate_max_lengths "${paths[@]}")";
 107
 108     for path in "${paths[@]}"; do
 109         IFS='/' read -r -a parts <<< "$path";
 110         formatted_path="";
 111         for i in "${!parts[@]}"; do
 112             if [[ $i -gt 0 ]]; then
 113                 formatted_path+="/";
 114             fi;
 115             formatted_path+="${parts[$i]}";
 116             if [[ $i -lt $((${#parts[@]} - 1)) ]]; then
 117                 formatted_path+=$(printf "%*s" $((${lengths[$i]} - ${#parts[$i]} + 1)) "");
 118             fi;
 119         done;
 120         echo "$formatted_path";
 121     done;
 122 }; # Function to format and align paths
 123 main() {
 124     { read_stdin; read_psarg "$@"; } | align_paths;
 125 }; # Call the function with the file paths
 126 main "$@";
 127
 128 # Author: Steven Baltakatei Sandoval
 129 # License; GPLv3+