1 files changed, 157 insertions, 0 deletions
diff --git a/mailsplit.c b/mailsplit.c
new file mode 100644
index 0000000000..189f4ed724
--- /dev/null
+++ b/mailsplit.c
@@ -0,0 +1,157 @@
+/*
+ * Totally braindamaged mbox splitter program.
+ *
+ * It just splits a mbox into a list of files: "0001" "0002" ..
+ * so you can process them further from there.
+ */
+#include <unistd.h>
+#include <stdlib.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <stdio.h>
+#include <assert.h>
+#include "cache.h"
+
+static const char git_mailsplit_usage[] =
+"git-mailsplit [-d<prec>] [<mbox>] <directory>";
+
+static int is_from_line(const char *line, int len)
+{
+	const char *colon;
+
+	if (len < 20 || memcmp("From ", line, 5))
+		return 0;
+
+	colon = line + len - 2;
+	line += 5;
+	for (;;) {
+		if (colon < line)
+			return 0;
+		if (*--colon == ':')
+			break;
+	}
+
+	if (!isdigit(colon[-4]) ||
+	    !isdigit(colon[-2]) ||
+	    !isdigit(colon[-1]) ||
+	    !isdigit(colon[ 1]) ||
+	    !isdigit(colon[ 2]))
+		return 0;
+
+	/* year */
+	if (strtol(colon+3, NULL, 10) <= 90)
+		return 0;
+
+	/* Ok, close enough */
+	return 1;
+}
+
+/* Could be as small as 64, enough to hold a Unix "From " line. */
+static char buf[4096];
+
+/* Called with the first line (potentially partial)
+ * already in buf[] -- normally that should begin with
+ * the Unix "From " line.  Write it into the specified
+ * file.
+ */
+static int split_one(FILE *mbox, const char *name)
+{
+	FILE *output = NULL;
+	int len = strlen(buf);
+	int fd;
+	int status = 0;
+
+	if (!is_from_line(buf, len))
+		goto corrupt;
+
+	fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
+	if (fd < 0)
+		die("cannot open output file %s", name);
+	output = fdopen(fd, "w");
+
+	/* Copy it out, while searching for a line that begins with
+	 * "From " and having something that looks like a date format.
+	 */
+	for (;;) {
+		int is_partial = (buf[len-1] != '\n');
+
+		if (fputs(buf, output) == EOF)
+			die("cannot write output");
+
+		if (fgets(buf, sizeof(buf), mbox) == NULL) {
+			if (feof(mbox)) {
+				status = 1;
+				break;
+			}
+			die("cannot read mbox");
+		}
+		len = strlen(buf);
+		if (!is_partial && is_from_line(buf, len))
+			break; /* done with one message */
+	}
+	fclose(output);
+	return status;
+
+ corrupt:
+	if (output)
+		fclose(output);
+	unlink(name);
+	fprintf(stderr, "corrupt mailbox\n");
+	exit(1);
+}
+
+int main(int argc, const char **argv)
+{
+	int i, nr, nr_prec = 4;
+	FILE *mbox = NULL;
+
+	for (i = 1; i < argc; i++) {
+		const char *arg = argv[i];
+
+		if (arg[0] != '-')
+			break;
+		/* do flags here */
+		if (!strncmp(arg, "-d", 2)) {
+			nr_prec = strtol(arg + 2, NULL, 10);
+			if (nr_prec < 3 || 10 <= nr_prec)
+				usage(git_mailsplit_usage);
+			continue;
+		}
+	}
+
+	/* Either one remaining arg (dir), or two (mbox and dir) */
+	switch (argc - i) {
+	case 1:
+		mbox = stdin;
+		break;
+	case 2:
+		if ((mbox = fopen(argv[i], "r")) == NULL)
+			die("cannot open mbox %s for reading", argv[i]);
+		break;
+	default:
+		usage(git_mailsplit_usage);
+	}
+	if (chdir(argv[argc - 1]) < 0)
+		usage(git_mailsplit_usage);
+
+	nr = 0;
+	if (fgets(buf, sizeof(buf), mbox) == NULL)
+		die("cannot read mbox");
+
+	for (;;) {
+		char name[10];
+
+		sprintf(name, "%0*d", nr_prec, ++nr);
+		switch (split_one(mbox, name)) {
+		case 0:
+			break;
+		case 1:
+			printf("%d\n", nr);
+			return 0;
+		default:
+			exit(1);
+		}
+	}
+}