add --help to batgrep

src/batgrep.sh

@@ -5,6 +5,117 @@
 # Repository: https://github.com/eth-p/bat-extras
 # Issues:     https://github.com/eth-p/bat-extras/issues
 # -----------------------------------------------------------------------------
+
+usage() {
+    cat <<-'EOF'
+Quickly search through and highlight files using ripgrep.
+
+Search through files or directories looking for matching regular expressions (or fixed strings with -F), and print the output using bat for an easy and syntax-highlighted experience.
+
+Usage: batgrep [OPTIONS] PATTERN [PATH...]
+
+Arguments:
+  [OPTIONS]
+          See Options below
+  PATTERN
+          Pattern passed to ripgrep
+  [PATH...]
+          Path(s) to search
+
+Options:
+  -i, --ingore-case:
+          Use case insensitive searching.
+
+  -s, --case-sensitive:
+          Use case sensitive searching.
+
+  -S, --smart-case:
+          Use smart case searching
+
+  -A, --after-context=[LINES]:
+          Display the next n lines after a matched line.
+
+  -B, --before-context=[LINES]:
+          Display the previous n lines before a matched line.
+
+  -C, --context=[LINES]:
+          A combination of --after-context and --before-context
+
+  -p, --search-pattern:
+          Tell pager to search for PATTERN. Currently supported pagers: less.
+
+      --no-follow:
+          Do not follow symlinks
+
+      --no-snip:
+          Do not show the snip decoration
+
+          This is automatically enabled when --context=0 or when bat --version is less than 0.12.x
+
+      --no-highlight:
+          Do not highlight matching lines.
+
+          This is automatically enabled when --context=0.
+
+      --color:
+          Force color output.
+
+      --no-color:
+          Force disable color output.
+
+      --paging=["never"/"always"]:
+          Enable/disable paging.
+
+      --pager=[PAGER]:
+          Specify the pager to use.
+
+      --terminal-wdith=[COLS]:
+          Generate output for the specified terminal width.
+
+      --no-seperator:
+          Disable printing separator between files
+
+Options passed directly to ripgrep:
+  -F, --fixed-strings
+
+  -U, --multiline
+
+  -P, --pcre2
+
+  -z, --search-zip
+
+  -w, --word-regexp
+
+      --one-file-system
+
+      --multiline-dotall
+
+      --ignore, --no-ignore
+
+      --crlf, --no-crlf
+
+      --hidden, --no-hidden
+
+  -E --encoding:
+          This is unsupported by bat, and may cause issues when trying to display unsupported encodings.
+
+  -g, --glob
+
+  -t, --type
+
+  -T, --type-not
+
+  -m, --max-count
+
+      --max-depth
+
+      --iglob
+
+      --ignore-file
+EOF
+    exit 1
+}
+
 # shellcheck disable=SC1090
 LIB="$(cd "$(dirname "${BASH_SOURCE[0]}")" && cd "$(dirname "$(readlink "${BASH_SOURCE[0]}" || echo ".")")/../lib" && pwd)"
 source "${LIB}/constants.sh"
@@ -82,6 +193,9 @@ SHIFTOPT_SHORT_OPTIONS="VALUE"
 while shiftopt; do
 	case "$OPT" in
 
+    # display help and quit
+    -h | --help) usage;;
+
 	# ripgrep options
 	[-]+([u]) ) ;;   # Ignore - handled in first loop.
 	--unrestricted)