trace.con commit cherry-pick: Suggest a better method to retain authorship (f52463a)
   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/* Stolen from "imap-send.c". */
  29static int git_vasprintf(char **strp, const char *fmt, va_list ap)
  30{
  31        int len;
  32        char tmp[1024];
  33
  34        if ((len = vsnprintf(tmp, sizeof(tmp), fmt, ap)) < 0 ||
  35            !(*strp = xmalloc(len + 1)))
  36                return -1;
  37        if (len >= (int)sizeof(tmp))
  38                vsprintf(*strp, fmt, ap);
  39        else
  40                memcpy(*strp, tmp, len + 1);
  41        return len;
  42}
  43
  44/* Stolen from "imap-send.c". */
  45int nfvasprintf(char **str, const char *fmt, va_list va)
  46{
  47        int ret = git_vasprintf(str, fmt, va);
  48        if (ret < 0)
  49                die("Fatal: Out of memory\n");
  50        return ret;
  51}
  52
  53/* Get a trace file descriptor from GIT_TRACE env variable. */
  54static int get_trace_fd(int *need_close)
  55{
  56        char *trace = getenv("GIT_TRACE");
  57
  58        if (!trace || !strcmp(trace, "") ||
  59            !strcmp(trace, "0") || !strcasecmp(trace, "false"))
  60                return 0;
  61        if (!strcmp(trace, "1") || !strcasecmp(trace, "true"))
  62                return STDERR_FILENO;
  63        if (strlen(trace) == 1 && isdigit(*trace))
  64                return atoi(trace);
  65        if (*trace == '/') {
  66                int fd = open(trace, O_WRONLY | O_APPEND | O_CREAT, 0666);
  67                if (fd == -1) {
  68                        fprintf(stderr,
  69                                "Could not open '%s' for tracing: %s\n"
  70                                "Defaulting to tracing on stderr...\n",
  71                                trace, strerror(errno));
  72                        return STDERR_FILENO;
  73                }
  74                *need_close = 1;
  75                return fd;
  76        }
  77
  78        fprintf(stderr, "What does '%s' for GIT_TRACE means ?\n", trace);
  79        fprintf(stderr, "If you want to trace into a file, "
  80                "then please set GIT_TRACE to an absolute pathname "
  81                "(starting with /).\n");
  82        fprintf(stderr, "Defaulting to tracing on stderr...\n");
  83
  84        return STDERR_FILENO;
  85}
  86
  87static const char err_msg[] = "Could not trace into fd given by "
  88        "GIT_TRACE environment variable";
  89
  90void trace_printf(const char *format, ...)
  91{
  92        char *trace_str;
  93        va_list rest;
  94        int need_close = 0;
  95        int fd = get_trace_fd(&need_close);
  96
  97        if (!fd)
  98                return;
  99
 100        va_start(rest, format);
 101        nfvasprintf(&trace_str, format, rest);
 102        va_end(rest);
 103
 104        write_or_whine_pipe(fd, trace_str, strlen(trace_str), err_msg);
 105
 106        free(trace_str);
 107
 108        if (need_close)
 109                close(fd);
 110}
 111
 112void trace_argv_printf(const char **argv, int count, const char *format, ...)
 113{
 114        char *argv_str, *format_str, *trace_str;
 115        size_t argv_len, format_len, trace_len;
 116        va_list rest;
 117        int need_close = 0;
 118        int fd = get_trace_fd(&need_close);
 119
 120        if (!fd)
 121                return;
 122
 123        /* Get the argv string. */
 124        argv_str = sq_quote_argv(argv, count);
 125        argv_len = strlen(argv_str);
 126
 127        /* Get the formated string. */
 128        va_start(rest, format);
 129        nfvasprintf(&format_str, format, rest);
 130        va_end(rest);
 131
 132        /* Allocate buffer for trace string. */
 133        format_len = strlen(format_str);
 134        trace_len = argv_len + format_len + 1; /* + 1 for \n */
 135        trace_str = xmalloc(trace_len + 1);
 136
 137        /* Copy everything into the trace string. */
 138        strncpy(trace_str, format_str, format_len);
 139        strncpy(trace_str + format_len, argv_str, argv_len);
 140        strcpy(trace_str + trace_len - 1, "\n");
 141
 142        write_or_whine_pipe(fd, trace_str, trace_len, err_msg);
 143
 144        free(argv_str);
 145        free(format_str);
 146        free(trace_str);
 147
 148        if (need_close)
 149                close(fd);
 150}