mailsplit: allow feeding mbox from standard input.

When mbox argument is missing, read the mailbox from the standard
input.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Documentation/git-mailsplit.txt b/Documentation/git-mailsplit.txt
index 66239a8..03a9477 100644 (file)
--- a/Documentation/git-mailsplit.txt
+++ b/Documentation/git-mailsplit.txt
@@ -7,7 +7,7 @@ git-mailsplit - Totally braindamaged mbox splitter program.
 
 SYNOPSIS
 --------
-'git-mailsplit' [-d<prec>] <mbox> <directory>
+'git-mailsplit' [-d<prec>] [<mbox>] <directory>
 
 DESCRIPTION
 -----------
@@ -17,7 +17,8 @@ directory so you can process them further from there.
 OPTIONS
 -------
 <mbox>::
-       Mbox file to split.
+       Mbox file to split.  If not given, the mbox is read from
+       the standard input.
 
 <directory>::
        Directory in which to place the individual messages.
@@ -31,6 +32,8 @@ OPTIONS
 Author
 ------
 Written by Linus Torvalds <torvalds@osdl.org>
+and Junio C Hamano <junkio@cox.net>
+
 
 Documentation
 --------------

diff --git a/mailsplit.c b/mailsplit.c
index bd7c611..7981f87 100644 (file)
--- a/mailsplit.c
+++ b/mailsplit.c
@@ -14,25 +14,10 @@
 #include <stdio.h>
 #include <ctype.h>
 #include <assert.h>
+#include "cache.h"
 
-static int usage(void)
-{
-       fprintf(stderr, "git-mailsplit [-d<prec>] <mbox> <directory>\n");
-       exit(1);
-}
-
-static int linelen(const char *map, unsigned long size)
-{
-       int len = 0, c;
-
-       do {
-               c = *map;
-               map++;
-               size--;
-               len++;
-       } while (size && c != '\n');
-       return len;
-}
+static const char git_mailsplit_usage[] =
+"git-mailsplit [-d<prec>] [<mbox>] <directory>";
 
 static int is_from_line(const char *line, int len)
 {
@@ -65,88 +50,110 @@ static int is_from_line(const char *line, int len)
        return 1;
 }
 
-static int parse_email(const void *map, unsigned long size)
+/* 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)
 {
-       unsigned long offset;
+       FILE *output = NULL;
+       int len = strlen(buf);
+       int fd;
+       int status = 0;
 
-       if (size < 6 || memcmp("From ", map, 5))
+       if (!is_from_line(buf, len))
                goto corrupt;
 
-       /* Make sure we don't trigger on this first line */
-       map++; size--; offset=1;
+       fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
+       if (fd < 0)
+               die("cannot open output file %s", name);
+       output = fdopen(fd, "w");
 
-       /*
-        * Search for a line beginning with "From ", and 
-        * having something that looks like a date format.
+       /* Copy it out, while searching for a line that begins with
+        * "From " and having something that looks like a date format.
         */
-       do {
-               int len = linelen(map, size);
-               if (is_from_line(map, len))
-                       return offset;
-               map += len;
-               size -= len;
-               offset += len;
-       } while (size);
-       return offset;
-
-corrupt:
+       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, char **argv)
+int main(int argc, const char **argv)
 {
-       int fd, nr, nr_prec = 4;
-       struct stat st;
-       unsigned long size;
-       void *map;
-
-       if (argc == 4 && !strncmp(argv[1], "-d", 2)) {
-               nr_prec = strtol(argv[1] + 2, NULL, 10);
-               if (nr_prec < 3 || 10 <= nr_prec)
-                       usage();
-               argc--; argv++;
-       }
-       if (argc != 3)
-               usage();
-       fd = open(argv[1], O_RDONLY);
-       if (fd < 0) {
-               perror(argv[1]);
-               exit(1);
-       }
-       if (chdir(argv[2]) < 0)
-               usage();
-       if (fstat(fd, &st) < 0) {
-               perror("stat");
-               exit(1);
+       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;
+               }
        }
-       size = st.st_size;
-       map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
-       if (map == MAP_FAILED) {
-               perror("mmap");
-               close(fd);
-               exit(1);
+
+       /* 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);
        }
-       close(fd);
+       if (chdir(argv[argc - 1]) < 0)
+               usage(git_mailsplit_usage);
+
        nr = 0;
-       do {
+       if (fgets(buf, sizeof(buf), mbox) == NULL)
+               die("cannot read mbox");
+
+       for (;;) {
                char name[10];
-               unsigned long len = parse_email(map, size);
-               assert(len <= size);
+
                sprintf(name, "%0*d", nr_prec, ++nr);
-               fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
-               if (fd < 0) {
-                       perror(name);
-                       exit(1);
-               }
-               if (write(fd, map, len) != len) {
-                       perror("write");
+               switch (split_one(mbox, name)) {
+               case 0:
+                       break;
+               case 1:
+                       printf("%d\n", nr);
+                       return 0;
+               default:
                        exit(1);
                }
-               close(fd);
-               map += len;
-               size -= len;
-       } while (size > 0);
-       printf("%d\n", nr);
-       return 0;
+       }
 }