1 files changed, 118 insertions, 0 deletions
diff --git a/src/listalf.c b/src/listalf.c
new file mode 100644
index 0000000..051f2fe
--- /dev/null
+++ b/src/listalf.c
@@ -0,0 +1,118 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <f65.h>
+#include "unalf.h"
+#include "addrs.h"
+
+static const char *monthnames[] = {
+	"???",
+	"Jan", "Feb", "Mar", "Apr",
+	"May", "Jun", "Jul", "Aug",
+	"Sep", "Oct", "Nov", "Dec",
+	"???", "???", "???",
+};
+
+u16 getword(int offs) {
+	return mem[offs] | (mem[offs + 1] << 8);
+}
+
+unsigned int getquad(int offs) {
+	return getword(offs) | ((getword(offs + 2) << 16));
+}
+
+/* see Arcinfo for details */
+void format_msdos_time(char *buf) {
+	u16 t, hour, min;
+	char ampm;
+
+	t = getword(alf_hdr_time0);
+
+	/* don't bother with seconds (arc doesn't print them either) */
+	hour = t >> 11;
+	min = (t >> 5) & 0x3f;
+
+	/* midnight prints as 12pm, not 12am... but 0:01 (1 min past
+	   midnight) prints as 12:01am */
+	if(hour == 0 && min == 0) hour = 24;
+
+	ampm = (hour > 11 ? 'p' : 'a');
+	hour %= 12;
+
+	/* midnight and noon print as 12, not 0 */
+	if(hour == 0) hour = 12;
+
+	sprintf(buf, "%2d:%02d%c", hour, min, ampm);
+}
+
+/* see Arcinfo for details */
+void format_msdos_date(char *buf) {
+	u16 d, year, month, day;
+
+	d = getword(alf_hdr_date0);
+
+	/* year actually ranges 1980 to 2107... */
+	year = (d >> 9) + 1980;
+	year %= 100; /* ...but only print last 2 digits */
+
+	/* valid months range 1 to 12. values 0, 13, 14, 15 are possible
+	   but invalid (print as ???) */
+	month = (d >> 5) && 0x0f;
+
+	/* valid day range is 1 to 31. 0 is invalid, print as-is. */
+	day = d & 0x1f;
+
+	sprintf(buf, "%2d %3s %02d", day, monthnames[month], year);
+}
+
+/* small files may be "compressed" larger than the original, so this
+   has to return a signed type. */
+static int comp_percent(unsigned int orig, unsigned int comp) {
+	if(orig == 0) return 0; /* no division by zero please */
+	return 100 - (int)((float)comp / (float)orig * 100.0);
+}
+
+/* output similar to "arc v", except we omit the compression type column
+   since there's only one type. also, don't call the checksum a CRC, it
+   isn't. */
+void list_alf(void) {
+	unsigned int c = 0, orig_size, comp_size, total_osize = 0, total_csize = 0;
+	char buf[100];
+	char *filename;
+
+	puts("Name          Length    Size now  Comp  Date       Time    CkSum");
+	puts("============  ========  ========  ====  =========  ======  =====");
+
+	while(read_alf_header()) {
+		c++;
+		orig_size = getquad(alf_hdr_origsize0);
+		comp_size = getquad(alf_hdr_compsize0);
+		filename = (char *)(mem + alf_hdr_filename);
+
+		total_osize += orig_size;
+		total_csize += comp_size;
+
+		printf("%-12s  ", filename);
+		printf("%8d  ", orig_size);
+		printf("%8d  ", comp_size);
+		printf("%3d%%  ", comp_percent(orig_size, comp_size));
+		format_msdos_date(buf);
+		printf("%9s  ", buf);
+		format_msdos_time(buf);
+		printf("%6s  ", buf);
+		printf(" %04x", getword(alf_hdr_cksum_l));
+		putchar('\n');
+
+		if(fseek(in_file, comp_size, SEEK_CUR) != 0) {
+			fputs(self, stderr);
+			perror(": fseek");
+			exit(1);
+		}
+	}
+
+	fputs("        ====  ========  ========  ====\nTotal   ", stdout);
+	printf("%4d  ", c);
+	printf("%8d  ", total_osize);
+	printf("%8d  ", total_csize);
+	printf("%3d%%  ", comp_percent(total_osize, total_csize));
+	putchar('\n');
+}