What are other bash operators?

In addition to && (AND) and || (OR), there are several other operators in bash that you can use for various purposes. Here are some common ones:

1. Logical Operators

• ! : Logical NOT operator. It negates the exit status of a command.

  ! command  # Executes the command and returns true if it fails.

2. Comparison Operators

• -eq : Equal to
• -ne : Not equal to
• -lt : Less than
• -le : Less than or equal to
• -gt : Greater than
• -ge : Greater than or equal to

  if [ "$a" -eq "$b" ]; then
      echo "a is equal to b"
  fi

3. File Test Operators

• -e : Checks if a file exists.
• -f : Checks if it is a regular file.
• -d : Checks if it is a directory.
• -s : Checks if a file is not empty.
• -r : Checks if a file is readable.
• -w : Checks if a file is writable.
• -x : Checks if a file is executable.

  if [ -f "file.txt" ]; then
      echo "file.txt exists and is a regular file."
  fi

4. Arithmetic Operators

• + : Addition
• - : Subtraction
• * : Multiplication
• / : Division
• % : Modulus

  result=$((a + b))

5. String Operators

• = : Checks if two strings are equal.
• != : Checks if two strings are not equal.
• -z : Checks if a string is empty.
• -n : Checks if a string is not empty.

  if [ -z "$string" ]; then
      echo "String is empty."
  fi

6. Redirection Operators

• > : Redirects output to a file (overwrites).
• >> : Redirects output to a file (appends).
• < : Redirects input from a file.
• 2> : Redirects standard error to a file.

  command > output.txt  # Redirects output to output.txt
  command 2> error.txt  # Redirects errors to error.txt

These operators can be combined in various ways to create complex scripts and command sequences in bash.