[PR] dylanaraps/neofetch#1543 from Syphist - Strip color codes from ascii art line length calculations

Upstream PR: https://github.com/dylanaraps/neofetch/pull/1543
Thanks to @Syphist

Co-authored-by: Syphist <thesyphist@gmail.com>

neofetch

@@ -39,7 +39,7 @@ sys_locale=${LANG:-C}
 XDG_CONFIG_HOME=${XDG_CONFIG_HOME:-${HOME}/.config}
 PATH=$PATH:/usr/xpg4/bin:/usr/sbin:/sbin:/usr/etc:/usr/libexec
 reset='\e[0m'
-shopt -s nocasematch
+shopt -s nocasematch extglob
 
 # Speed up script by not using unicode.
 LC_ALL=C
@@ -4580,6 +4580,26 @@ image_backend() {
     [[ "$image_backend" != "off" ]] && printf '\e[%sA\e[9999999D' "${lines:-0}"
 }
 
+# From pull request #1220, this is a fast way to strip character codes
+strip_escape_codes() {
+    local input="${1//\"/\\\"}" output="" i char within_code=0
+    for ((i=0; i < ${#input}; ++i)); do
+        char="${input:i:1}"
+        if (( within_code == 1 )); then
+            case "${char}" in
+                [a-zA-Z]) within_code=0 ;;
+            esac
+            continue
+        fi
+        if [[ "${char}" == $'\e' ]]; then
+            within_code=1
+            continue
+        fi
+        output+="${char}"
+    done
+    eval "$2=\"${output}\""
+}
+
 print_ascii() {
     if [[ -f "$image_source" && ! "$image_source" =~ (png|jpg|jpeg|jpe|svg|gif) ]]; then
         ascii_data="$(< "$image_source")"
@@ -4598,8 +4618,12 @@ print_ascii() {
         lines=$ascii_lines
     else
         while IFS=$'\n' read -r line; do
-            line=${line//\\\\/\\}
             line=${line//█/ }
+            # Fast method to strip codes
+            strip_escape_codes "${line}" line
+            # Use patterns to replace color codes that the above line did not catch
+            line=${line//\\033\[*([0-9;])[JKmsu]/}
+            line=${line//\[*([0-9;])[JKmsu]/}
             ((++lines,${#line}>ascii_len)) && ascii_len="${#line}"
         done <<< "${ascii_data//\$\{??\}}"
     fi