fix: Stdin with forbidden character

Implementation relies on nested `sed` command. When stdin contains default delimiter, substitutions returns error.
macie · Feb 6, 2024 · 5b57ea9 · 5b57ea9
1 parent 5687529
commit 5b57ea9
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diff --git a/README.md b/README.md
@@ -110,6 +110,19 @@ cat result
 
 For more information, see [ARG_MAX, maximum length of arguments for a new process](https://www.in-ulm.de/~mascheck/various/argmax/).
 
+### unknown option to `s'
+
+`smallstache` uses special character to separate key-value pairs in substitution
+command (default: `|`). When value contains this character, `smallstache` will
+throw an error similar to:
+
+```
+sed: -e expression #1, char 24: unknown option to `s'
+```
+
+In such case, you should use another character as a delimiter, for example:
+`smallstache -d _`.
+
 ## License
 
 [MIT](./LICENSE) ([explanation in simple words](https://tldrlegal.com/license/mit-license))
diff --git a/smallstache b/smallstache
@@ -8,13 +8,31 @@
 
 
 # following line is used by `make cli-release`
-smallstache_version=24.1
+smallstache_version=24.02
 
+smallstache_delimiter='|'
 smallstache_verbosity_level=0
 
 # parse flags
 for arg in "$@"; do
 	case "$arg" in
+		-d)
+			shift
+			case "$1" in
+				-*)
+					echo 'smallstache: missing delimiter. See "smallstache -h" for help' >&2
+					exit 64
+					;;
+				*)
+					if [ "${#1}" -ne 1 ]; then
+						echo 'smallstache: invalid delimiter. See "smallstache -h" for help' >&2
+						exit 64
+					fi
+					smallstache_delimiter="$1"
+					shift
+					;;
+			esac
+			;;
 		-h|--help)
 			if [ "$#" -gt 1 ]; then
 				echo 'smallstache: invalid arguments. See "smallstache -h" for help' >&2
@@ -28,11 +46,13 @@ for arg in "$@"; do
 				   smallstache [-h | --help] [-v | --version]
 
 				Options:
+				   -d CHAR                Use CHAR as a regex delimiter (default: `|`).
 				   -h, --help             Show this help and exit.
 				   -v, --version          Show version number and exit.
 				   --verbose              Print debugging messages.
 
 				Value from stdin KEY=VALUE pairs substitutes `{{KEY}}` in TEMPLATE_FILE.
+				Stdin cannot contain CHAR delimiter.
 				EOF
 			exit 0
 			;;
@@ -77,11 +97,17 @@ case "$#" in
 		;;
 esac
 
+smallstache_template=$1
+
 # transform each stdin line in form `KEY=VALUE` into `s|{{ *KEY *}}|VALUE|g; `
-smallstache_regex=$(sed 's_\([^=]*\)=\(.*\)_s|{{ *\1 *}}|\2|g; _g')
+smallstache_sed_regex="s_\([^=]*\)=\(.*\)_s${smallstache_delimiter}{{ *\1 *}}${smallstache_delimiter}\2${smallstache_delimiter}g; _g"
+if ! smallstache_sed_command=$(sed "${smallstache_sed_regex}" 2>/dev/null); then
+	printf 'smallstache: key contains delimiter character "%s". Change delimiter with "smallstache -d CHAR"\n' "${smallstache_delimiter}" >&2
+	exit 64
+fi
 if [ "${smallstache_verbosity_level}" -gt 0 ]; then
 	echo '# Sed commands to be used on template file' >&2
-	echo "${smallstache_regex}" >&2 
+	echo "${smallstache_sed_command}" >&2 
 fi
 
-sed -e "${smallstache_regex}" "$1"
+sed -e "${smallstache_sed_command}" "${smallstache_template}"
diff --git a/tests/test_data.sh b/tests/test_data.sh
@@ -1,11 +1,11 @@
 #!/bin/sh
 
 beforeAll() {
-    FIXTURES=$(mktemp -d -t 'smallstache_testXXXXXX')
+	FIXTURES=$(mktemp -d -t 'smallstache_testXXXXXX')
 }
 
 afterEach() {
-    rm -R "${FIXTURES:-/tmp/smallstache}"/* 2>/dev/null
+	rm -R "${FIXTURES:-/tmp/smallstache}"/* 2>/dev/null
 }
 
 afterAll() {
@@ -17,54 +17,70 @@ afterAll() {
 #
 
 test_text() {
-    echo "Do {{ who }} feel {{ how }}?" >"${FIXTURES}/template"
-    printf "who=I\nhow=lucky\n" >"${FIXTURES}/data"
-    echo "Do I feel lucky?" >"${FIXTURES}/want"
+	echo "Do {{ who }} feel {{ how }}?" >"${FIXTURES}/template"
+	printf "who=I\nhow=lucky\n" >"${FIXTURES}/data"
+	echo "Do I feel lucky?" >"${FIXTURES}/want"
 
-    <"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
+	<"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
 
-    diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
+	diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
 }
 
 test_number() {
-    echo "e^{{ exp }} = {{ product }}" >"${FIXTURES}/template"
-    printf "exp=0\nproduct=1.001\n" >"${FIXTURES}/data"
-    echo "e^0 = 1.001" >"${FIXTURES}/want"
+	echo "e^{{ exp }} = {{ product }}" >"${FIXTURES}/template"
+	printf "exp=0\nproduct=1.001\n" >"${FIXTURES}/data"
+	echo "e^0 = 1.001" >"${FIXTURES}/want"
 
-    <"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
+	<"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
 
-    diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
+	diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
 }
 
 test_partial() {
-    echo "{{ sth }} ipsum {{ else }} sit {{ what }}" >"${FIXTURES}/template"
-    printf "sth=Lorem\n" >"${FIXTURES}/data"
-    echo "Lorem ipsum {{ else }} sit {{ what }}" >"${FIXTURES}/want"
+	echo "{{ sth }} ipsum {{ else }} sit {{ what }}" >"${FIXTURES}/template"
+	printf "sth=Lorem\n" >"${FIXTURES}/data"
+	echo "Lorem ipsum {{ else }} sit {{ what }}" >"${FIXTURES}/want"
 
-    <"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
+	<"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
 
-    diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
+	diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
 }
 
 test_multiline() {
-    cat >"${FIXTURES}/template" <<-'EOF'
+	cat >"${FIXTURES}/template" <<-'EOF'
 		Numbah {{ day_no }} day of Christmas
 		My tutu gave to me
 		{{ gifts }}
 		EOF
-    cat >"${FIXTURES}/data" <<-'EOF'
+	cat >"${FIXTURES}/data" <<-'EOF'
 		day_no=three
 		gifts=3 dried squid\n2 coconuts and\nOne mynah bird in one papaya tree
 		EOF
-    cat >"${FIXTURES}/want" <<-'EOF'
+	cat >"${FIXTURES}/want" <<-'EOF'
 		Numbah three day of Christmas
 		My tutu gave to me
 		3 dried squid
 		2 coconuts and
 		One mynah bird in one papaya tree
 		EOF
 
-    <"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
+	<"${FIXTURES}/data" ./smallstache "${FIXTURES}/template" >"${FIXTURES}/got"
 
-    diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
+	diff "${FIXTURES}/want" "${FIXTURES}/got" >&2
+}
+
+test_delimiter_in_key() {
+	echo '{{ ke_y }}' >"${FIXTURES}/template"
+	echo "ke_y=value" | ./smallstache -d _ "${FIXTURES}/template" 2>"${FIXTURES}/error_msg"
+
+	test $? -eq 64
+	test -s "${FIXTURES}/error_msg"
+}
+
+test_delimiter_in_value() {
+	echo '{{ key }}' >"${FIXTURES}/template"
+	echo "key=val|ue" | ./smallstache "${FIXTURES}/template" 2>"${FIXTURES}/error_msg"
+
+	test $? -eq 1
+	test -s "${FIXTURES}/error_msg"
 }
diff --git a/tests/test_usage.sh b/tests/test_usage.sh
@@ -39,6 +39,13 @@ test_verbose() {
     diff "${FIXTURES}/empty_file" "${FIXTURES}/got"
 }
 
+test_invalid_delimiter() {
+    ./smallstache -d __ 2>"${FIXTURES}/error_msg"
+
+    test $? -eq 64
+    test -s "${FIXTURES}/error_msg"
+}
+
 test_no_args() {
     ./smallstache 2>"${FIXTURES}/error_msg"