gitk: Second try to work around the command line limit on Windows
[git/dscho.git] / trace.c
blob4229ae1231d69aedd9f1aa8350989ddbe2bdb845
1 /*
2 * GIT - The information manager from hell
4 * Copyright (C) 2000-2002 Michael R. Elkins <me@mutt.org>
5 * Copyright (C) 2002-2004 Oswald Buddenhagen <ossi@users.sf.net>
6 * Copyright (C) 2004 Theodore Y. Ts'o <tytso@mit.edu>
7 * Copyright (C) 2006 Mike McCormack
8 * Copyright (C) 2006 Christian Couder
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #include "cache.h"
26 #include "quote.h"
28 /* Get a trace file descriptor from GIT_TRACE env variable. */
29 static int get_trace_fd(int *need_close)
31 char *trace = getenv("GIT_TRACE");
33 if (!trace || !strcmp(trace, "") ||
34 !strcmp(trace, "0") || !strcasecmp(trace, "false"))
35 return 0;
36 if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
37 return STDERR_FILENO;
38 if (strlen(trace) == 1 && isdigit(*trace))
39 return atoi(trace);
40 if (is_absolute_path(trace)) {
41 int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
42 if (fd == -1) {
43 fprintf(stderr,
44 "Could not open '%s' for tracing: %s\n"
45 "Defaulting to tracing on stderr...\n",
46 trace, strerror(errno));
47 return STDERR_FILENO;
49 *need_close = 1;
50 return fd;
53 fprintf(stderr, "What does '%s' for GIT_TRACE mean?\n", trace);
54 fprintf(stderr, "If you want to trace into a file, "
55 "then please set GIT_TRACE to an absolute pathname "
56 "(starting with /).\n");
57 fprintf(stderr, "Defaulting to tracing on stderr...\n");
59 return STDERR_FILENO;
62 static const char err_msg[] = "Could not trace into fd given by "
63 "GIT_TRACE environment variable";
65 void trace_printf(const char *fmt, ...)
67 struct strbuf buf;
68 va_list ap;
69 int fd, len, need_close = 0;
71 fd = get_trace_fd(&need_close);
72 if (!fd)
73 return;
75 strbuf_init(&buf, 64);
76 va_start(ap, fmt);
77 len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
78 va_end(ap);
79 if (len >= strbuf_avail(&buf)) {
80 strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
81 va_start(ap, fmt);
82 len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
83 va_end(ap);
84 if (len >= strbuf_avail(&buf))
85 die("broken vsnprintf");
87 strbuf_setlen(&buf, len);
89 write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
90 strbuf_release(&buf);
92 if (need_close)
93 close(fd);
96 void trace_argv_printf(const char **argv, const char *fmt, ...)
98 struct strbuf buf;
99 va_list ap;
100 int fd, len, need_close = 0;
102 fd = get_trace_fd(&need_close);
103 if (!fd)
104 return;
106 strbuf_init(&buf, 64);
107 va_start(ap, fmt);
108 len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
109 va_end(ap);
110 if (len >= strbuf_avail(&buf)) {
111 strbuf_grow(&buf, len - strbuf_avail(&buf) + 128);
112 va_start(ap, fmt);
113 len = vsnprintf(buf.buf, strbuf_avail(&buf), fmt, ap);
114 va_end(ap);
115 if (len >= strbuf_avail(&buf))
116 die("broken vsnprintf");
118 strbuf_setlen(&buf, len);
120 sq_quote_argv(&buf, argv, 0);
121 strbuf_addch(&buf, '\n');
122 write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
123 strbuf_release(&buf);
125 if (need_close)
126 close(fd);