Bash function that compares two files with color-coded printing

compare_files.sh

compare_files() {
  if [ "$#" -ne 2 ]; then
    echo "Usage: compare_files <file1> <file2>"
    return 1
  fi

  local file1="$1"
  local file2="$2"

  if [ ! -f "$file1" ]; then
    echo "Error: File '$file1' not found."
    return 1
  fi

  if [ ! -f "$file2" ]; then
    echo "Error: File '$file2' not found."
    return 1
  fi

  diff_output=$(diff -u "$file1" "$file2")
  diff_exit_code=$?

  if [ $diff_exit_code -eq 0 ]; then
    echo "Files '$file1' and '$file2' are identical."
  else
    echo "Differences between '$file1' and '$file2':"
    while IFS= read -r line; do
      case "$line" in
        -*)
          # Deletions (red)
          echo -e "\x1b[31m$line\x1b[37m"
          ;;
        +*)
          # Additions (green)
          echo -e "\x1b[32m$line\x1b[37m"
          ;;
        *)
          # Unchanged (default color)
          echo -e "\x1b[37m$line\x1b[37m"
          ;;
      esac
    done <<< "$diff_output"
  fi
}

Example use:

echo 'hello' >> test1.txt
echo 'hello\nworld' >> test2.txt
echo 'hello world' >> test3.txt

compare_files test1.txt test2.txt                                    
Differences between 'test1.txt' and 'test2.txt':
--- test1.txt	2024-06-29 11:51:12
+++ test2.txt	2024-06-29 11:51:19
@@ -1 +1,2 @@
 hello
+world

compare_files test1.txt test3.txt
Differences between 'test1.txt' and 'test3.txt':
--- test1.txt	2024-06-29 11:51:12
+++ test3.txt	2024-06-29 11:51:24
@@ -1 +1 @@
-hello
+hello world

compare_files test2.txt test3.txt
Differences between 'test2.txt' and 'test3.txt':
--- test2.txt	2024-06-29 11:51:19
+++ test3.txt	2024-06-29 11:51:24
@@ -1,2 +1 @@
-hello
-world
+hello world