alf: Sanity-check generated Atari filenames.

1 files changed, 72 insertions, 0 deletions

diff --git a/src/sanity.c b/src/sanity.c
new file mode 100644
index 0000000..ccbcae1
--- /dev/null
+++ b/src/sanity.c
@@ -0,0 +1,72 @@
+#include <stdio.h>
+#include <string.h>
+
+#ifndef u8
+#define u8 unsigned char
+#endif
+
+extern const char *self;
+
+void bad_atari_filename(const char *fname, const char *msg) {
+	char fn[50] = "";
+	char xbuf[5];
+	int i;
+	u8 c;
+
+	for(i = 0; (c = (u8)fname[i]) && i < 12; i++) {
+		if(c < ' ' || c > '|') {
+			/* not printable, insert a hex escape */
+			sprintf(xbuf, "$%02X", c);
+			strcat(fn, xbuf);
+		} else {
+			strncat(fn, (char *)&c, 1);
+		}
+	}
+
+	fprintf(stderr, "%s: warning: bad Atari filename \"%s\": %s\n", self, fn, msg);
+}
+
+/* note to self: it's tempting to use isalpha(), isprint(), etc
+	from ctype.h... but those are locale-aware. we want ASCII-only
+	versions. */
+void sanity_check_filename(const char *fname) {
+	u8 c;
+	unsigned int i, bad = 0, dots = 0, uscore = 0;
+
+	c = fname[0];
+	if(!c) {
+		bad_atari_filename(fname, "empty!");
+		return;
+	} else if(c < 'A' || c > 'Z') {
+		bad_atari_filename(fname, "does not begin with A-Z");
+	}
+
+	for(i = 0; (c = fname[i]) && i < 12; i++) {
+		if(c >= 'A' && c <= 'Z')
+			continue;
+		if(c >= '0' && c <= '9')
+			continue;
+		if(c == '_') {
+			uscore++;
+			continue;
+		}
+		if(c == '.') {
+			dots++;
+			continue;
+		}
+		bad++;
+	}
+
+	if(!dots) {
+		bad_atari_filename(fname, "no \".\"");
+	} else if(dots > 1) {
+		bad_atari_filename(fname, "more than one \".\"");
+	}
+
+	if(bad)
+		bad_atari_filename(fname, "invalid characters.");
+	else if(uscore)
+		fprintf(stderr, "%s: filename has underscore, OK on Sparta/MyDOS, not Atari DOS 2.x\n", self);
+}
+
+