#!/usr/bin/env bash # ----------------------------------------------------------------------------- # bat-extras | Copyright (C) 2019 eth-p | MIT License # # Repository: https://github.com/eth-p/bat-extras # Issues: https://github.com/eth-p/bat-extras/issues # ----------------------------------------------------------------------------- # Returns 0 (true) if the current pager is less, otherwise 1 (false). is_pager_less() { [[ "$(pager_name)" = "less" ]] return $? } # Returns 0 (true) if the current pager is bat, otherwise 1 (false). is_pager_bat() { [[ "$(pager_name)" = "bat" ]] return $? } # Returns 0 (true) if the current pager is disabled, otherwise 1 (false). is_pager_disabled() { [[ -z "$(pager_name)" ]] return $? } # Prints the detected pager name. pager_name() { _detect_pager 1>&2 echo "$_SCRIPT_PAGER_NAME" } # Prints the detected pager version. pager_version() { _detect_pager 1>&2 echo "$_SCRIPT_PAGER_VERSION" } # Executes a command or function, and pipes its output to the pager (if it exists). # # Returns: The exit code of the command. # Example: # pager_exec echo hi pager_exec() { if [[ -n "$SCRIPT_PAGER_CMD" ]]; then "$@" | pager_display return $? else "$@" return $? fi } # Displays the output of a command or function inside the pager (if it exists). # # Example: # bat | pager_display pager_display() { if [[ -n "$SCRIPT_PAGER_CMD" ]]; then if [[ -n "$SCRIPT_PAGER_ARGS" ]]; then "${SCRIPT_PAGER_CMD[@]}" "${SCRIPT_PAGER_ARGS[@]}" return $? else "${SCRIPT_PAGER_CMD[@]}" return $? fi else cat return $? fi } # ----------------------------------------------------------------------------- # Detect the pager information. # shellcheck disable=SC2120 _detect_pager() { if [[ "$_SCRIPT_PAGER_DETECTED" = "true" ]]; then return; fi _SCRIPT_PAGER_DETECTED=true # If the pager command is empty, the pager is disabled. if [[ -z "${SCRIPT_PAGER_CMD[0]}" ]]; then _SCRIPT_PAGER_VERSION=0 _SCRIPT_PAGER_NAME="" return; fi # Determine the pager name and version. local output local output1 output="$("${SCRIPT_PAGER_CMD[0]}" --version 2>&1)" output1="$(head -n 1 <<<"$output")" if [[ "$output1" =~ ^less[[:blank:]]([[:digit:]]+) ]]; then _SCRIPT_PAGER_VERSION="${BASH_REMATCH[1]}" _SCRIPT_PAGER_NAME="less" elif [[ "$output1" =~ ^bat(cat)?[[:blank:]]([[:digit:]]+) ]]; then # shellcheck disable=SC2034 __BAT_VERSION="${BASH_REMATCH[2]}" _SCRIPT_PAGER_VERSION="${BASH_REMATCH[2]}" _SCRIPT_PAGER_NAME="bat" else _SCRIPT_PAGER_VERSION=0 _SCRIPT_PAGER_NAME="$(basename "${SCRIPT_PAGER_CMD[0]}")" fi } # Configure the script pager. # This attempts to mimic how bat determines the pager and pager arguments. # # 1. Use BAT_PAGER # 2. Use PAGER with special arguments for less # 3. Use PAGER _configure_pager() { # shellcheck disable=SC2206 SCRIPT_PAGER_CMD=($PAGER) SCRIPT_PAGER_ARGS=() # Prefer the bat pager. if [[ -n "${BAT_PAGER+x}" ]]; then # [note]: This is intentional. # shellcheck disable=SC2206 SCRIPT_PAGER_CMD=($BAT_PAGER) SCRIPT_PAGER_ARGS=() return fi # If the pager is bat, use less instead. if is_pager_bat; then SCRIPT_PAGER_CMD=("less") SCRIPT_PAGER_ARGS=() fi # Add arguments for the less pager. if is_pager_less; then SCRIPT_PAGER_CMD=("${SCRIPT_PAGER_CMD[0]}" -R --quit-if-one-screen) if [[ "$(pager_version)" -lt 500 ]]; then SCRIPT_PAGER_CMD+=(--no-init) fi fi } # ----------------------------------------------------------------------------- if [[ -t 1 ]]; then # Detect and choose the arguments for the pager. _configure_pager else # Prefer no pager if not a tty. SCRIPT_PAGER_CMD=() SCRIPT_PAGER_ARGS=() fi