1/*
2 * Totally braindamaged mbox splitter program.
3 *
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 <string.h>
13#include <stdio.h>
14#include <assert.h>
15#include "cache.h"
16
17static const char git_mailsplit_usage[] =
18"git-mailsplit [-d<prec>] [<mbox>] <directory>";
19
20static int is_from_line(const char *line, int len)
21{
22 const char *colon;
23
24 if (len < 20 || memcmp("From ", line, 5))
25 return 0;
26
27 colon = line + len - 2;
28 line += 5;
29 for (;;) {
30 if (colon < line)
31 return 0;
32 if (*--colon == ':')
33 break;
34 }
35
36 if (!isdigit(colon[-4]) ||
37 !isdigit(colon[-2]) ||
38 !isdigit(colon[-1]) ||
39 !isdigit(colon[ 1]) ||
40 !isdigit(colon[ 2]))
41 return 0;
42
43 /* year */
44 if (strtol(colon+3, NULL, 10) <= 90)
45 return 0;
46
47 /* Ok, close enough */
48 return 1;
49}
50
51/* Could be as small as 64, enough to hold a Unix "From " line. */
52static char buf[4096];
53
54/* Called with the first line (potentially partial)
55 * already in buf[] -- normally that should begin with
56 * the Unix "From " line. Write it into the specified
57 * file.
58 */
59static int split_one(FILE *mbox, const char *name)
60{
61 FILE *output = NULL;
62 int len = strlen(buf);
63 int fd;
64 int status = 0;
65
66 if (!is_from_line(buf, len))
67 goto corrupt;
68
69 fd = open(name, O_WRONLY | O_CREAT | O_EXCL, 0666);
70 if (fd < 0)
71 die("cannot open output file %s", name);
72 output = fdopen(fd, "w");
73
74 /* Copy it out, while searching for a line that begins with
75 * "From " and having something that looks like a date format.
76 */
77 for (;;) {
78 int is_partial = (buf[len-1] != '\n');
79
80 if (fputs(buf, output) == EOF)
81 die("cannot write output");
82
83 if (fgets(buf, sizeof(buf), mbox) == NULL) {
84 if (feof(mbox)) {
85 status = 1;
86 break;
87 }
88 die("cannot read mbox");
89 }
90 len = strlen(buf);
91 if (!is_partial && is_from_line(buf, len))
92 break; /* done with one message */
93 }
94 fclose(output);
95 return status;
96
97 corrupt:
98 if (output)
99 fclose(output);
100 unlink(name);
101 fprintf(stderr, "corrupt mailbox\n");
102 exit(1);
103}
104
105int main(int argc, const char **argv)
106{
107 int i, nr, nr_prec = 4;
108 FILE *mbox = NULL;
109
110 for (i = 1; i < argc; i++) {
111 const char *arg = argv[i];
112
113 if (arg[0] != '-')
114 break;
115 /* do flags here */
116 if (!strncmp(arg, "-d", 2)) {
117 nr_prec = strtol(arg + 2, NULL, 10);
118 if (nr_prec < 3 || 10 <= nr_prec)
119 usage(git_mailsplit_usage);
120 continue;
121 }
122 }
123
124 /* Either one remaining arg (dir), or two (mbox and dir) */
125 switch (argc - i) {
126 case 1:
127 mbox = stdin;
128 break;
129 case 2:
130 if ((mbox = fopen(argv[i], "r")) == NULL)
131 die("cannot open mbox %s for reading", argv[i]);
132 break;
133 default:
134 usage(git_mailsplit_usage);
135 }
136 if (chdir(argv[argc - 1]) < 0)
137 usage(git_mailsplit_usage);
138
139 nr = 0;
140 if (fgets(buf, sizeof(buf), mbox) == NULL)
141 die("cannot read mbox");
142
143 for (;;) {
144 char name[10];
145
146 sprintf(name, "%0*d", nr_prec, ++nr);
147 switch (split_one(mbox, name)) {
148 case 0:
149 break;
150 case 1:
151 printf("%d\n", nr);
152 return 0;
153 default:
154 exit(1);
155 }
156 }
157}