aboutsummaryrefslogtreecommitdiff
path: root/mailsplit.c
blob: eb58b1ebe430a1a1acf189097c5277545e3b67e9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
/*
 * 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>] [-f<n>] [-b] -o<directory> <mbox>...";

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, int allow_bare)
{
	FILE *output = NULL;
	int len = strlen(buf);
	int fd;
	int status = 0;
	int is_bare = !is_from_line(buf, len);

	if (is_bare && !allow_bare)
		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_bare && 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 nr = 0, nr_prec = 4;
	int allow_bare = 0;
	const char *dir = NULL;
	const char **argp;
	static const char *stdin_only[] = { "-", NULL };
	char *name;

	for (argp = argv+1; *argp; argp++) {
		const char *arg = *argp;

		if (arg[0] != '-')
			break;
		/* do flags here */
		if ( arg[1] == 'd' ) {
			nr_prec = strtol(arg+2, NULL, 10);
			if (nr_prec < 3 || 10 <= nr_prec)
				usage(git_mailsplit_usage);
			continue;
		} else if ( arg[1] == 'f' ) {
			nr = strtol(arg+2, NULL, 10);
		} else if ( arg[1] == 'b' && !arg[2] ) {
			allow_bare = 1;
		} else if ( arg[1] == 'o' && arg[2] ) {
			dir = arg+2;
		} else if ( arg[1] == '-' && !arg[2] ) {
			argp++;	/* -- marks end of options */
			break;
		} else {
			die("unknown option: %s", arg);
		}
	}

	if ( !dir ) {
		/* Backwards compatibility: if no -o specified, accept
		   <mbox> <dir> or just <dir> */
		switch (argc - (argp-argv)) {
		case 1:
			dir = argp[0];
			argp = stdin_only;
			break;
		case 2:
			stdin_only[0] = argp[0];
			dir = argp[1];
			argp = stdin_only;
			break;
		default:
			usage(git_mailsplit_usage);
		}
	} else {
		/* New usage: if no more argument, parse stdin */
		if ( !*argp )
			argp = stdin_only;
	}

	name = xmalloc(strlen(dir) + 2 + 3 * sizeof(nr));

	while (*argp) {
		const char *file = *argp++;
		FILE *f = !strcmp(file, "-") ? stdin : fopen(file, "rt");
		int file_done = 0;

		if ( !f )
			die ("cannot open mbox %s", file);

		if (fgets(buf, sizeof(buf), f) == NULL)
			die("cannot read mbox %s", file);

		while (!file_done) {
			sprintf(name, "%s/%0*d", dir, nr_prec, ++nr);
			file_done = split_one(f, name, allow_bare);
		}

		if (f != stdin)
			fclose(f);
	}

	printf("%d\n", nr);
	return 0;
}