Implement -a (append) option

1 files changed, 21 insertions, 7 deletions

diff --git a/repl.c b/repl.c
index 9991338..3794a17 100644
--- a/repl.c
+++ b/repl.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <signal.h>
+#include <string.h>
 #include <err.h>
 #include <readline/readline.h>
 #include <readline/history.h>
@@ -13,16 +14,26 @@ void handle_int() { /* handle ctrl-c */
 	rl_redisplay(); /* thanks James Taylor on Stack Overflow */
 }
 
+void usage(char **argv) {
+	fprintf(stderr, "usage: %s [-a] command\n", argv[0]);
+	exit(1);
+}
+
 int main(int argc, char *argv[]) {
-	if (argc != 2) {
-		fprintf(stderr, "usage: %s command\n", argv[0]);
-		return 1;
+	bool append = false;
+
+	if (argc < 2 || argc > 3)
+		usage(argv);
+	if (argc > 1 && argv[1][0] == '-') {
+		if (argv[1][1] != 'a' || argc < 3)
+			usage(argv);
+		append = true;
 	}
 
-	int size = strlen(argv[1]) + 3 + 1;
+	int size = strlen(argv[argc-1]) + 3 + 1;
 	char *prompt = malloc(size);
 	if (prompt == NULL) err(1, NULL);
-	snprintf(prompt, size, "%s > ", argv[1]);
+	snprintf(prompt, size, "%s > ", argv[argc-1]);
 
 	struct sigaction act = {0};
 	act.sa_handler = handle_int;
@@ -40,10 +51,13 @@ int main(int argc, char *argv[]) {
 		
 		if (input[0] != '\0') add_history(input);
 
-		int size = strlen(argv[1]) + 1 + strlen(input) + 1;
+		int size = strlen(argv[argc-1]) + 1 + strlen(input) + 1;
 		char *command = malloc(size);
 		if (command == NULL) err(1, NULL);
-		snprintf(command, size, "%s %s", argv[1], input);
+		if (append)
+			snprintf(command, size, "%s %s", input, argv[argc-1]);
+		else
+			snprintf(command, size, "%s %s", argv[argc-1], input);
 
 		system(command);