bat-extras/lib/pager.sh

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#!/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 $?
}
# Returns 0 (true) if the current pager is disabled, otherwise 1 (false)
is_pager_disabled() {
[[ -z "$(pager_name)" ]]
return $?
}
# Gets the name of the pager command.
pager_name() {
if [[ -z "${SCRIPT_PAGER_CMD[0]}" ]]; then return; fi
if [[ -z "$_SCRIPT_PAGER_NAME" ]]; then
local output="$("${SCRIPT_PAGER_CMD[0]}" --version 2>&1)"
if head -n 1 <<< "$output" | grep '^less \d' &>/dev/null; then
_SCRIPT_PAGER_NAME="less"
else
_SCRIPT_PAGER_NAME="$(basename "${SCRIPT_PAGER_CMD[0]}")"
fi
fi
echo "$_SCRIPT_PAGER_NAME"
}
# Executes a command or function, and pipes its output to the pager (if exists).
#
# Returns: The exit code of the command.
# Example:
# pager_exec echo hi
pager_exec() {
if [[ -n "$1" ]]; then
if [[ -n "$SCRIPT_PAGER_CMD" ]]; then
"$@" | "${SCRIPT_PAGER_CMD[@]}" "${SCRIPT_PAGER_ARGS[@]}"
return $?
else
"$@"
return $?
fi
fi
}
# Displays the output of a command or function inside the pager (if exists).
#
# Example:
# bat | pager_display
pager_display() {
if [[ -n "$SCRIPT_PAGER_CMD" ]]; then
"${SCRIPT_PAGER_CMD[@]}" "${SCRIPT_PAGER_ARGS[@]}"
else
cat
fi
}
# -----------------------------------------------------------------------------
# Defaults.
SCRIPT_PAGER_CMD=("$PAGER")
SCRIPT_PAGER_ARGS=()
# Add arguments for the less pager.
if is_pager_less; then
SCRIPT_PAGER_ARGS=(-R)
fi
# Prefer the bat pager.
if [[ -n "${BAT_PAGER+x}" ]]; then
SCRIPT_PAGER_CMD=($BAT_PAGER)
SCRIPT_PAGER_ARGS=()
fi
# Prefer no pager if not a tty.
if ! [[ -t 1 ]]; then
SCRIPT_PAGER_CMD=()
SCRIPT_PAGER_ARGS=()
fi