From: Steven Baltakatei Sandoval <baltakatei@gmail.com>
Date: Mon, 15 Jul 2024 23:33:54 +0000 (+0000)
Subject: feat(user/zeropad.sh):Remove unnecessary leading zeroes
X-Git-Url: https://zdv2.bktei.com/gitweb/BK-2020-03.git/commitdiff_plain/0564bc200e84856a1ab37483439bad0900b00552?ds=sidebyside

feat(user/zeropad.sh):Remove unnecessary leading zeroes
---

diff --git a/user/zeropad.sh b/user/zeropad.sh
index b9b032b..242b30b 100755
--- a/user/zeropad.sh
+++ b/user/zeropad.sh
@@ -4,7 +4,7 @@
 # Example: zeropad.sh;
 #          zeropad.sh ".jpg";
 # Input: arg1  str  file extension of files to apply changes to
-# Version: 0.1.1
+# Version: 0.2.0
 
 declare fext; # file extension
 
@@ -20,31 +20,55 @@ list_files() {
             | grep -E -- "${fext}$" ;
     fi;
 }; # list pwd file basenames
+remove_leading_zeroes() {
+    # Desc: Removes leading zeroes from lines
+    # Input: stdin
+    # Output: stdout
+    # Depends: BK-2020-03 read_stdin()
+    # Version: 0.0.1
+    while read -r line; do
+        printf "%s\n" "$line" | sed -E -e 's/(^0*)([0-9].*)/\2/';
+    done;
+};
+get_max_digits() {
+    # Desc: Returns max leading digits of pwd filenames
+    # Depends: list_files()
+    #          BK-2020-03:  remove_leading_zeroes()
+    #          GNU sed 4.8
+    #          GNU awk 5.1.0
+    local output;
+    
+    # Find the maximum number of leading digits in the filenames of working dir
+    output="$(list_files | remove_leading_zeroes \
+        | awk '{ match($0, /^[0-9]+/); if (RLENGTH > max) max=RLENGTH } END { print max }' )";
+    # declare -p max_digits; # debug
+    printf "%s" "$output";
+}; # return max digits to stdout
 main () {
     # Read file extension if provided
     if [[ -n "$1" ]]; then
         fext="$1";
     fi;
 
-    # Find the maximum number of leading digits in the filenames of working dir
-    max_digits="$(list_files | sed -e 's/[^0-9].*//' | awk '{ if(length > L) L=length } END { print L }')";
-    # declare -p max_digits; # debug
+    max_digits="$(get_max_digits)";
 
     # Loop over the files and rename them
     while read -r file; do
+        # Skip files with no leading digits
         re='^[0-9]+';
         if [[ ! "$file" =~ $re ]]; then continue; fi;
 
         # Extract the leading digits
-        digits="$(echo "$file" | sed 's/\([0-9]*\).*/\1/')";
+        digits="$(echo "$file" | sed -E 's/([0-9]*).*/\1/')"; # all leading digits
+        digits_nlz="$(echo "$digits" | remove_leading_zeroes)"; # no leading zeroes
         # Zero-pad the digits
-        padded_digits="$(printf "%0${max_digits}d" "$digits")";
+        padded_digits="$(printf "%0${max_digits}d" "$digits_nlz")";
         # Construct the new filename
         new_file="${padded_digits}${file#${digits}}";
         # Rename the file
         if [[ "$file" == "$new_file" ]]; then continue; fi;
-        mv -n "$file" "$new_file"
-        # declare -p file new_file; # debug
+        mv -n "$file" "$new_file";
+        #declare -p max_digits file digits digits_nlz padded_digits new_file # debug
     done < <(list_files);
 }; # main program