main: support invoking utpl interpreter through shebang

Signed-off-by: Jo-Philipp Wich <jo@mein.io>

2 files changed, 21 insertions, 0 deletions

diff --git a/ast.h b/ast.h
index 480f537..52e22e8 100644
--- a/ast.h
+++ b/ast.h
@@ -83,6 +83,7 @@ struct ut_state {
 	uint8_t trim_blocks:1;
 	uint8_t lstrip_blocks:1;
 	uint8_t strict_declarations:1;
+	uint8_t skip_shebang:1;
 	size_t off;
 	enum ut_block_type blocktype;
 	struct {
diff --git a/main.c b/main.c
index f80f80b..a23a39d 100644
--- a/main.c
+++ b/main.c
@@ -148,6 +148,16 @@ parse(struct ut_state *state, const char *source, bool dumponly,
 	enum ut_error_type err;
 	char *msg;
 
+	if (state->skip_shebang) {
+		if (source[0] == '#' && source[1] == '!') {
+			while (source[0] != '\0' && source[0] != '\n')
+				source++;
+
+			if (source[0] == '\n')
+				source++;
+		}
+	}
+
 	err = ut_parse(state, source);
 
 	if (!err) {
@@ -336,6 +346,16 @@ main(int argc, char **argv)
 		}
 	}
 
+	if (!srcstr && !srcfile && argv[optind] != NULL) {
+		srcfile = read_file(argv[optind]);
+		state->skip_shebang = 1;
+
+		if (!srcfile) {
+			rv = UT_ERROR_EXCEPTION;
+			goto out;
+		}
+	}
+
 	if ((srcstr && srcfile) || (!srcstr && !srcfile)) {
 		fprintf(stderr, srcstr ? "Options -i and -s are exclusive\n" : "One of -i or -s is required\n");