trace.con commit Merge branch 'jk/maint-1.6.0-trace-argv' (2beba6b)
   1/*
   2 * GIT - The information manager from hell
   3 *
   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
   9 *
  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.
  14 *
  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.
  19 *
  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
  23 */
  24
  25#include "cache.h"
  26#include "quote.h"
  27
  28/* Get a trace file descriptor from GIT_TRACE env variable. */
  29static int get_trace_fd(int *need_close)
  30{
  31        char *trace = getenv("GIT_TRACE");
  32
  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;
  48                }
  49                *need_close = 1;
  50                return fd;
  51        }
  52
  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");
  58
  59        return STDERR_FILENO;
  60}
  61
  62static const char err_msg[] = "Could not trace into fd given by "
  63        "GIT_TRACE environment variable";
  64
  65void trace_printf(const char *fmt, ...)
  66{
  67        struct strbuf buf;
  68        va_list ap;
  69        int fd, len, need_close = 0;
  70
  71        fd = get_trace_fd(&need_close);
  72        if (!fd)
  73                return;
  74
  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");
  86        }
  87        strbuf_setlen(&buf, len);
  88
  89        write_or_whine_pipe(fd, buf.buf, buf.len, err_msg);
  90        strbuf_release(&buf);
  91
  92        if (need_close)
  93                close(fd);
  94}
  95
  96void trace_argv_printf(const char **argv, const char *fmt, ...)
  97{
  98        struct strbuf buf;
  99        va_list ap;
 100        int fd, len, need_close = 0;
 101
 102        fd = get_trace_fd(&need_close);
 103        if (!fd)
 104                return;
 105
 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");
 117        }
 118        strbuf_setlen(&buf, len);
 119
 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);
 124
 125        if (need_close)
 126                close(fd);
 127}