dabba/dabba.c

   1 /**
   2  * \file dabba.c
   3  * \author written by Emmanuel Roullit emmanuel.roullit@gmail.com (c) 2012
   4  * \date 2012
   5  */
   6
   7 /* __LICENSE_HEADER_BEGIN__ */
   8
   9 /*
  10  * Copyright (C) 2012   Emmanuel Roullit <emmanuel.roullit@gmail.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or (at
  15  * your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful, but
  18  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  19  * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  20  * for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along
  23  * with this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St, Fifth Floor, Boston, MA 02110, USA
  25  *
  26  */
  27
  28 /* __LICENSE_HEADER_END__ */
  29
  30 /*
  31
  32 =head1 NAME
  33
  34 dabba - Send queries to dabbad and process its replies.
  35
  36 =head1 SYNOPSIS
  37
  38 dabba <command> <arguments> [--help]
  39
  40 =head1 DESCRIPTION
  41
  42 dabba is here to generate IPC queries to dabbad and output its
  43 replies formatted in a YAML output
  44
  45 =head1 OPTIONS
  46
  47 =over
  48
  49 =item --help
  50
  51 Prints help output and the currently supported commands.
  52
  53 =back
  54
  55 =head1 AUTHOR
  56
  57 Written by Emmanuel Roullit <emmanuel.roullit@gmail.com>
  58
  59 =head1 BUGS
  60
  61 =over
  62
  63 =item Please report bugs to <https://github.com/eroullit/dabba/issues>
  64
  65 =item dabba project project page: <https://github.com/eroullit/dabba>
  66
  67 =back
  68
  69 =head1 COPYRIGHT
  70
  71 =over
  72
  73 =item Copyright © 2012 Emmanuel Roullit.
  74
  75 =item License GPLv2+: GNU GPL version 2 or later <http://gnu.org/licenses/gpl.html>.
  76
  77 =item This is free software: you are free to change and redistribute it.
  78
  79 =item There is NO WARRANTY, to the extent permitted by law.
  80
  81 =back
  82
  83 =cut
  84
  85 */
  86
  87 #include <stdio.h>
  88 #include <stdlib.h>
  89 #include <string.h>
  90 #include <unistd.h>
  91 #include <assert.h>
  92 #include <errno.h>
  93 #include <sys/stat.h>
  94
  95 #include <libdabba/macros.h>
  96 #include <dabbad/dabbad.h>
  97 #include <dabba/dabba.h>
  98 #include <dabba/help.h>
  99 #include <dabba/interface.h>
 100 #include <dabba/capture.h>
 101
 102 int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 103 {
 104         int status;
 105         struct stat st;
 106
 107         assert(p);
 108
 109         status = p->fn(argc, argv);
 110         if (status)
 111                 return status;
 112
 113         /* Somebody closed stdout? */
 114         if (fstat(fileno(stdout), &st))
 115                 return 0;
 116         /* Ignore write errors for pipes and sockets.. */
 117         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 118                 return 0;
 119
 120         /* Check for ENOSPC and EIO errors.. */
 121         if (fflush(stdout)) {
 122                 perror("write failure on standard output");
 123                 return (errno);
 124         }
 125
 126         if (ferror(stdout)) {
 127                 perror("unknown write failure on standard output");
 128                 return (1);
 129         }
 130
 131         if (fclose(stdout)) {
 132                 perror("close failed on standard output");
 133                 return (errno);
 134         }
 135
 136         return 0;
 137 }
 138
 139 static int handle_internal_command(int argc, const char **argv)
 140 {
 141         size_t i;
 142         const char *cmd = argv[0];
 143         static struct cmd_struct commands[] = {
 144                 {"interface", cmd_interface},
 145                 {"capture", cmd_capture},
 146                 {"help", cmd_help}
 147         };
 148
 149         if (argc == 0 || cmd == NULL || !strcmp(cmd, "--help"))
 150                 cmd = "help";
 151
 152         /* Turn "dabba cmd --help" into "dabba help cmd" */
 153         if (argc > 1 && !strcmp(argv[1], "--help")) {
 154                 argv[1] = argv[0];
 155                 argv[0] = cmd = "help";
 156         }
 157
 158         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 159                 struct cmd_struct *p = commands + i;
 160                 if (strcmp(p->cmd, cmd))
 161                         continue;
 162
 163                 argc--;
 164                 argv++;
 165
 166                 return (run_builtin(p, argc, argv));
 167         }
 168
 169         help_unknown_cmd(cmd);
 170
 171         return ENOSYS;
 172 }
 173
 174 int main(int argc, const char **argv)
 175 {
 176         assert(argc);
 177         assert(argv);
 178
 179         argc--;
 180         argv++;
 181
 182         return (handle_internal_command(argc, argv));
 183 }