bin/re: Add working utility

1 files changed, 97 insertions, 0 deletions

diff --git a/bin/re b/bin/re
new file mode 100755
index 0000000..c600aee
--- /dev/null
+++ b/bin/re
@@ -0,0 +1,97 @@
+#!/bin/sh
+set -eu
+
+
+usage() {
+	cat <<-'EOF'
+		Usage:
+		  re 'REGEXP' [FILE...]
+		  re -h
+	EOF
+}
+
+help() {
+	cat <<-'EOF'
+
+
+		Options:
+		  -h, --help    show this message
+
+		  REGEXP        the regular expresion to match and replace
+
+
+		Execute a find and replace on files in a repository when
+		no FILE... is given, listing them via "vcs ls" from vcs(1), or
+		on the given FILE... list.
+
+		EXPRESSION is to be forwarded to sed(1) directly.
+
+
+		Examples:
+
+		  Replace "weak" with "week" on the whole repository:
+
+		    $ re 's/weak/week/g'
+
+
+		  Delete lines beginning with "import" on package.py:
+
+		    $ re '/^import/d' package.py
+	EOF
+}
+
+
+for flag in "$@"; do
+	case "$flag" in
+		--)
+			break
+			;;
+		--help)
+			usage
+			help
+			exit
+			;;
+		*)
+			;;
+	esac
+done
+
+while getopts 'h' flag; do
+	case "$flag" in
+		h)
+			usage
+			help
+			exit
+			;;
+		*)
+			usage >&2
+			exit 2
+			;;
+	esac
+done
+shift $((OPTIND - 1))
+
+REGEXP="${1:-}"
+eval "$(assert-arg -- "$REGEXP" 'REGEXP')"
+shift
+
+
+replace() {
+	FILE="$1"
+	if ! sed "$REGEXP" < "$FILE" | cmp -s - "$FILE"; then
+		if [ ! -e "$FILE" ]; then
+			return 1
+		fi
+		sed "$REGEXP" < "$FILE" | sponge "$FILE"
+	fi
+}
+
+if [ -n "${1:-}" ]; then
+	for f in "$@"; do
+		replace "$f"
+	done
+else
+	vcs ls | while read -r f; do
+		replace "$f"
+	done
+fi