precmd example

        warp_escape_ps1 () {
           tr '\n\n' ' ' <<< "$*" | xxd -p | tr -d '\n'
        }
        
                # Format a string value according to JSON syntax - Adapted from https://github.com/lework/script.
        warp_escape_json () {
            # Explanation of the sed replacements (each command is separated by a `;`):
            # s/(["\\])/\\\1/g - Replace all double-quote (") and backslash (\) characters with the escaped versions (\" and \\)
            # s/\b/\\b/g - Replace all backspace characters with \b
            # s/\t/\\t/g - Replace all tab characters with \t
            # s/\f/\\f/g - Replace all form feed characters with \f
            # s/\r/\\r/g - Replace all carriage return characters with \r
            # $!s/$/\\n/ - On every line except the last, insert the \n escape at the end of the line
            #              Note: sed acts line-by-line, so it doesn't see the literal newline characters to replace
            #
            # tr -d '\n' - Remove the literal newlines from the final output
            #
            # Additional note: In a shell script between single quotes ('), no escape sequences are interpreted.
            # To work around that and insert the literal values into the regular expressions, we stop the single-quote,
            # then add the literal using ANSI-C syntax ($'\t'), then start a new single-quote. That is the meaning
            # behind the various `'$'\b''` blocks in the command. All of these separate strings are then concatenated
            # together to form the full argument to send to sed.
            sed -E 's/(["\\])/\\\1/g; s/'$'\b''/\\b/g; s/'$'\t''/\\t/g; s/'$'\f''/\\f/g; s/'$'\r''/\\r/g; $!s/$/\\n/' <<<"$*" | tr -d '\n'
        }
        
        warp_precmd () {
            # $? is relative to the process so we MUST check this first
            # or else the exit code will correspond to the commands
            # executed within this block instead of the actual last
            # command that was run.
            local exit_code=$?
            # Clear the prompt again before the command is rendered as it could
            # have been reset by the user's bashrc or by setting the variable
            # on the command line.
            if [[ -n $PS1 ]]; then
              WARP_PS1="$PS1"
            fi
            unset PS1
            unset PROMPT
            # Escaped PS1 variable
            local escaped_ps1
            if [[ $WARP_FEATURE_FLAG_HONOR_PS1 == "1" ]]; then
              # Tricking the shell into rendering the prompt
              # Note that in more modern versions of bash we could use ${PS1@P} to achieve the same,
              # but macOs comes by default with a much older version of bash, and we want to be compatible.
              deref_ps1=$(echo -e "\n"  | PS1="$WARP_PS1" bash --norc -i 2>&1 | head -2 | tail -1)
              escaped_ps1=$(warp_escape_ps1 "$(echo "$deref_ps1")")
            fi
            # Flush history
            history -a
            # Reset the custom kill-whole-line binding as the user's bashrc (which is sourced after bashrc_warp)
            # could have added another bind. This won't have any user-impact because these shortcuts are only run
            # in the context of the bash editor, which isn't displayed in Warp.
            bind -r '"\C-p"'
            bind "\C-p":kill-whole-line
            local escaped_pwd
            escaped_pwd=$(warp_escape_json "$PWD")
            local escaped_virtual_env=""
            if [ ! -z "$VIRTUAL_ENV" ]; then
                escaped_virtual_env=$(warp_escape_json "$VIRTUAL_ENV")
            fi
            local escaped_conda_env=""
            if [ ! -z "$CONDA_DEFAULT_ENV" ]; then
                escaped_conda_env=$(warp_escape_json "$CONDA_DEFAULT_ENV")
            fi
            local git_branch
            git_branch=$(git rev-parse --abbrev-ref HEAD 2>/dev/null || echo "")
            local escaped_git_branch
            escaped_git_branch=$(warp_escape_json "$git_branch")
            # At this point, escaped prompt looks something like
            # \\u{001B}\\u{005B}\\u{0030}\\u{0031}\\u{003B} ...
            # We need to maintain the double quoting of \\u in the message that
            # is sent otherwise the receiving side will interpret the value
            # as JS string literals of the form \uHEX, and will include
            # ctrl characters (like ESC) in the json, which will cause a JSON
            # parse error.
            # Note WARP_SESSION_ID doesn't need to be escaped since it's a number
            local escaped_json="{\"hook\": \"Precmd\", \"value\": {\"pwd\": \"$escaped_pwd\", \"ps1\": \"$escaped_ps1\", \"git_branch\": \"$escaped_git_branch\", \"virtual_env\": \"$escaped_virtual_env\", \"conda_env\": \"$escaped_conda_env\", \"exit_code\": $exit_code, \"session_id\": $WARP_SESSION_ID}}"
            warp_send_message "$escaped_json"
        }