Implement append, overwrite options for alf. Also -h/--help.

1 files changed, 56 insertions, 10 deletions

diff --git a/src/alf.c b/src/alf.c
index 8a230a2..0dd8d88 100644
--- a/src/alf.c
+++ b/src/alf.c
@@ -8,6 +8,10 @@
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
+#include <unistd.h>
+#include <limits.h>
+
+#define self "unalf"
 
 #ifndef u8
 #define u8 unsigned char
@@ -28,6 +32,9 @@ u8 output_buf[MAX_INPUT_SIZE];
 u8 byte_tokens[256];
 int input_len, output_len, out_bitpos;
 
+int opt_append = 0;
+int opt_overwrite = 0;
+
 typedef struct s_token {
 	u8 *start;
 	u16 length;
@@ -185,15 +192,15 @@ int match_token(int pos) {
 
 void make_token(int start, int end) {
 	if(curr_token == max_token) {
-		printf("%d: curr_token %d == max_token, ", in_pos, curr_token);
+		// printf("%d: curr_token %d == max_token, ", in_pos, curr_token);
 		if(token_bits == MAX_BITS) {
-			printf("token_bits %d == MAX_BITS, reset\n", token_bits);
+			// printf("token_bits %d == MAX_BITS, reset\n", token_bits);
 			store_token(TOK_RESET); /* stored at the *old* token size! */
 			token_bits = 9;
 			init_table();
 			return;
 		} else {
-			printf("token_bits %d < MAX_BITS, inc\n", token_bits);
+			// printf("token_bits %d < MAX_BITS, inc\n", token_bits);
 			token_bits++;
 		}
 		max_token = 1 << token_bits;
@@ -242,26 +249,65 @@ void crunch_file(const char *filename) {
 
 	create_header();
 
+	/* crunches the entire input to memory! */
 	crunch();
+
 	fwrite(output_buf, 1, output_len, out_file);
 }
 
+void make_backup(void) {
+	char bak[PATH_MAX + 2];
+	strncpy(bak, out_filename, PATH_MAX);
+	strcat(bak, "~");
+	rename(out_filename, bak);
+}
+
 int main(int argc, char **argv) {
-	if(argc < 3) {
-		fprintf(stderr, "usage: alf archive.alf file [file ...]\n");
+	int opt;
+
+	if(argc < 2 || !strcmp(argv[1], "--help") || !strcmp(argv[1], "-h")) {
+		fprintf(stderr, "Usage: %s [-a|-o] archive.alf file [file ...]\n", self);
+		fprintf(stderr, "Options:\n");
+		fprintf(stderr, "  -a: append to archive\n");
+		fprintf(stderr, "  -o: overwrite archive (don't make backup with ~)\n");
 		exit(1);
 	}
 
-	argv++;
-	out_file = fopen(*argv, "wb");
+	while((opt = getopt(argc, argv, "ao")) != -1) {
+		switch(opt) {
+			case 'a': opt_append = 1; opt_overwrite = 1; break;
+			case 'o': opt_overwrite = 1; opt_append = 0; break;
+			default:
+				fprintf(stderr, "%s: fatal: invalid option '-%c' (try -h or --help)\n", self, optopt);
+				exit(1);
+		}
+	}
+
+	if(optind >= argc) {
+		fprintf(stderr, "%s: fatal: missing alf file argument (try -h or --help)\n", self);
+		exit(1);
+	}
+
+	out_filename = argv[optind];
+
+	optind++;
+
+	if(optind >= argc) {
+		fprintf(stderr, "%s: fatal: no filenames (nothing to compress) (try -h or --help)\n", self);
+		exit(1);
+	}
+
+	if(!opt_overwrite) make_backup();
+
+	out_file = fopen(out_filename, opt_append ? "ab" : "wb");
 	if(!out_file) {
 		perror(*argv);
 		exit(1);
 	}
-	argv++;
 
-	while(*argv)
-		crunch_file(*argv++);
+	while(optind < argc) {
+		crunch_file(argv[optind++]);
+	}
 
 	fclose(out_file);