Add batwatch script

src/batwatch.sh

@@ -0,0 +1,148 @@
+#!/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
+# -----------------------------------------------------------------------------
+LIB="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)/../lib"
+BAT="bat"
+DOCS_URL="https://github.com/eth-p/bat-extras/blob/master/doc"
+source "${LIB}/opt.sh"
+source "${LIB}/opt_hooks.sh"
+source "${LIB}/print.sh"
+source "${LIB}/pager.sh"
+# -----------------------------------------------------------------------------
+# Init:
+# -----------------------------------------------------------------------------
+hook_color
+hook_pager
+# -----------------------------------------------------------------------------
+# Watchers:
+# -----------------------------------------------------------------------------
+
+WATCHERS=("entr")
+
+# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 
+
+watcher_entr_watch() {
+	ENTR_ARGS=()
+
+	if [[ "$OPT_CLEAR" = "true" ]]; then
+		ENTR_ARGS+=('-c')
+	fi
+
+	entr "${ENTR_ARGS[@]}" \
+		"$BAT" "${BAT_ARGS[@]}" \
+		--terminal-width="$TERM_WIDTH" \
+		--paging=never \
+		"$@" \
+		< <(printf "%s\n" "$@")
+}
+
+watcher_entr_supported() {
+	command -v entr &>/dev/null
+	return $?
+}
+
+
+# -----------------------------------------------------------------------------
+# Functions:
+# -----------------------------------------------------------------------------
+
+determine_watcher() {
+	local watcher
+	for watcher in "${WATCHERS[@]}"; do
+		if "watcher_${watcher}_supported"; then
+			echo "$watcher"
+			return 0
+		fi
+	done
+	
+	return 1
+}
+
+# -----------------------------------------------------------------------------
+# Options:
+# -----------------------------------------------------------------------------
+BAT_ARGS=()
+FILES=()
+FILES_HAS_DIRECTORY=false
+OPT_CLEAR=true
+OPT_WATCHER=""
+TERM_WIDTH="$(tput cols)"
+
+# Set options based on tty.
+if [[ -t 1 ]]; then
+	OPT_COLOR=true
+fi
+
+# Parse arguments.
+while shiftopt; do
+	case "$OPT" in
+
+		# Script Options
+		--watcher)        shiftval; OPT_WATCHER="$OPT_VAL";;
+		--clear)                    OPT_CLEAR=true;;
+		--no-clear)                 OPT_CLEAR=false;;
+		--terminal-width) shiftval; TERM_WIDTH="$OPT_VAL";;
+
+		# Bat/Pager Options
+		-*) BAT_ARGS+=("$OPT=$OPT_VAL");;
+		
+		# Files
+		*) {
+			FILES+=("$OPT")
+		};;		
+
+	esac
+done
+
+if [[ -z "$FILES" ]]; then
+    print_error "no files provided"
+    exit 1
+fi
+
+for file in "${FILES[@]}"; do
+	if ! [[ -e "$file" ]]; then
+		print_error "'%s' does not exist"
+		exit 1
+	fi
+
+	if [[ -d "$file" ]]; then
+		FILES_HAS_DIRECTORY=true
+	fi
+done
+
+# Append bat arguments.
+if "$OPT_COLOR"; then
+	BAT_ARGS+=("--color=always")
+else
+	BAT_ARGS+=("--color=never")
+fi
+
+# -----------------------------------------------------------------------------
+# Main:
+# -----------------------------------------------------------------------------
+main() {
+	if [[ -z "$OPT_WATCHER" ]]; then
+		OPT_WATCHER="$(determine_watcher)"
+		if [[ $? -ne 0 ]]; then
+			printc "%{RED}[%s error]%{CLEAR}: Your system does not have any supported watchers.\n" "$PROGRAM" 1>&2
+			printc "Please read the documentation at {BLUE}%s%{CLEAR} for more details.\n" "$DOCS_URL/batwatch.md" 1>&2
+			return 2
+		fi
+	fi
+
+	if ! type "watcher_${OPT_WATCHER}_supported" &>/dev/null; then
+		printc "%{RED}[%s error]%{CLEAR}: Unknown watcher: '%s'\n" "$PROGRAM" "$OPT_WATCHER" 1>&2
+		return 1
+	fi
+	
+	"watcher_${OPT_WATCHER}_watch" "${FILES[@]}"
+	return $?
+}
+
+pager_exec main
+exit $?
+