unalf: Add -n and -s options.

1 files changed, 72 insertions, 21 deletions

diff --git a/src/extract.c b/src/extract.c
index 98523db..6f24c0d 100644
--- a/src/extract.c
+++ b/src/extract.c
@@ -76,27 +76,81 @@ void set_datetime() {
 	}
 }
 
-void make_backup(void) {
+void make_backup(const char *fname) {
 	/* up to 12-char FILENAME.EXT, plus a ~, plus null terminator = 14 */
-	char backup[14];
+	/* has to handle up to 16 chars for -s option: LONGFILE.NAME.ALF */
+	char backup[20];
 
-	strncpy(backup, out_filename, 13);
-	strncat(backup, "~", 13);
+	strncpy(backup, fname, 19);
+	strncat(backup, "~", 19);
 
 	/* silently ignore errors! */
-	rename(out_filename, backup);
+	rename(fname, backup);
+}
+
+void open_out_file(const char *fname) {
+	if(opts.testonly) {
+		fname = "/dev/null";
+	} else if(!opts.overwrite) {
+		make_backup(fname);
+	}
+
+	if(!(out_file = fopen(fname, "wb"))) {
+		fprintf(stderr, "%s: fatal:  ", self);
+		perror(fname);
+		exit(1);
+	}
+}
+
+void truncated_err(void);
+
+void write_split_file(void) {
+	int i, c;
+	unsigned int len;
+	char splitname[20];
+
+	strncpy(splitname, out_filename, 13);
+	strncat(splitname, ".ALF", 6);
+
+	if(!opts.quiet)
+		printf("Writing %s\n", splitname);
+
+	len = getquad(alf_hdr_compsize0);
+
+	open_out_file(splitname);
+	fwrite(&mem[alf_header], 1, 29, out_file);
+	for(i = 0; i < len; i++) {
+		c = fgetc(in_file);
+		if(c == EOF) {
+			truncated_err();
+		}
+		fputc(c, out_file);
+	}
+	fclose(out_file);
 }
 
 void extract_alf(void) {
+	int files_extracted = 0, skip, file_number = 0;
+
 	/* get ready to call fake 6502 stuff. set up memory like the Atari. */
 	dpoke(MEMTOP, 0xbc1f);
 
 	while(read_alf_header()) {
+		file_number++;
+		skip = 0;
+
 		out_filename = (char *)(mem + alf_hdr_filename);
 
 		fix_filename();
 
-		if(!file_wanted(out_filename)) {
+		if(opts.extract_num)
+			skip = (opts.extract_num != file_number);
+		else
+			skip = !file_wanted(out_filename);
+
+		if(skip) {
+			if(!opts.quiet)
+				printf("Skipping %s\n", out_filename);
 			if(fseek(in_file, getquad(alf_hdr_compsize0), SEEK_CUR) != 0) {
 				fprintf(stderr, "%s: fatal: seek failed on input!\n", self);
 				exit(1);
@@ -105,6 +159,13 @@ void extract_alf(void) {
 			continue;
 		}
 
+		files_extracted++;
+
+		if(opts.split) {
+			write_split_file();
+			continue;
+		}
+
 		if(!opts.quiet) {
 			printf("%s %s\n", opts.testonly ? "Testing" : "Uncrunching", out_filename);
 		}
@@ -112,21 +173,7 @@ void extract_alf(void) {
 		if(opts.extract_to_stdout) {
 			out_file = stdout;
 		} else {
-			char *realname = out_filename;
-
-			if(opts.testonly) {
-				out_filename = "/dev/null";
-			} else if(!opts.overwrite) {
-				make_backup();
-			}
-
-			if(!(out_file = fopen(out_filename, "wb"))) {
-				fprintf(stderr, "%s: fatal:  ", self);
-				perror(out_filename);
-				exit(1);
-			}
-
-			out_filename = realname;
+			open_out_file(out_filename);
 		}
 
 		bad_checksum = bytes_written = 0;
@@ -153,6 +200,10 @@ void extract_alf(void) {
 		else
 			printf("All files OK.\n");
 	}
+
+	if(!opts.quiet && !files_extracted) {
+		printf("No files %s!\n", opts.testonly ? "tested" : "extracted");
+	}
 }
 
 void chksum_err(void) {