Merge branch 'fixes'
[git.git] / mailsplit.c
blob7afea1aaca6af966b6532ba66f7411d897a2874f
1 /*
2 * Totally braindamaged mbox splitter program.
4 * It just splits a mbox into a list of files: "0001" "0002" ..
5 * so you can process them further from there.
6 */
7 #include <unistd.h>
8 #include <stdlib.h>
9 #include <fcntl.h>
10 #include <sys/types.h>
11 #include <sys/stat.h>
12 #include <sys/mman.h>
13 #include <string.h>
14 #include <stdio.h>
15 #include <ctype.h>
16 #include <assert.h>
18 static int usage(void)
20 fprintf(stderr, "mailsplit <mbox> <directory>\n");
21 exit(1);
24 static int linelen(const char *map, unsigned long size)
26 int len = 0, c;
28 do {
29 c = *map;
30 map++;
31 size--;
32 len++;
33 } while (size && c != '\n');
34 return len;
37 static int is_from_line(const char *line, int len)
39 const char *colon;
41 if (len < 20 || memcmp("From ", line, 5))
42 return 0;
44 colon = line + len - 2;
45 line += 5;
46 for (;;) {
47 if (colon < line)
48 return 0;
49 if (*--colon == ':')
50 break;
53 if (!isdigit(colon[-4]) ||
54 !isdigit(colon[-2]) ||
55 !isdigit(colon[-1]) ||
56 !isdigit(colon[ 1]) ||
57 !isdigit(colon[ 2]))
58 return 0;
60 /* year */
61 if (strtol(colon+3, NULL, 10) <= 90)
62 return 0;
64 /* Ok, close enough */
65 return 1;
68 static int parse_email(const void *map, unsigned long size)
70 unsigned long offset;
72 if (size < 6 || memcmp("From ", map, 5))
73 goto corrupt;
75 /* Make sure we don't trigger on this first line */
76 map++; size--; offset=1;
79 * Search for a line beginning with "From ", and
80 * having something that looks like a date format.
82 do {
83 int len = linelen(map, size);
84 if (is_from_line(map, len))
85 return offset;
86 map += len;
87 size -= len;
88 offset += len;
89 } while (size);
90 return offset;
92 corrupt:
93 fprintf(stderr, "corrupt mailbox\n");
94 exit(1);
97 int main(int argc, char **argv)
99 int fd, nr;
100 struct stat st;
101 unsigned long size;
102 void *map;
104 if (argc != 3)
105 usage();
106 fd = open(argv[1], O_RDONLY);
107 if (fd < 0) {
108 perror(argv[1]);
109 exit(1);
111 if (chdir(argv[2]) < 0)
112 usage();
113 if (fstat(fd, &st) < 0) {
114 perror("stat");
115 exit(1);
117 size = st.st_size;
118 map = mmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0);
119 if (map == MAP_FAILED) {
120 perror("mmap");
121 close(fd);
122 exit(1);
124 close(fd);
125 nr = 0;
126 do {
127 char name[10];
128 unsigned long len = parse_email(map, size);
129 assert(len <= size);
130 sprintf(name, "%04d", ++nr);
131 fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
132 if (fd < 0) {
133 perror(name);
134 exit(1);
136 if (write(fd, map, len) != len) {
137 perror("write");
138 exit(1);
140 close(fd);
141 map += len;
142 size -= len;
143 } while (size > 0);
144 return 0;