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 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33 #include <unistd.h>
  34 #include <assert.h>
  35 #include <errno.h>
  36 #include <sys/stat.h>
  37
  38 #include <libdabba/macros.h>
  39 #include <dabbad/dabbad.h>
  40 #include <dabba/dabba.h>
  41 #include <dabba/help.h>
  42 #include <dabba/interface.h>
  43 #include <dabba/capture.h>
  44
  45 int run_builtin(struct cmd_struct *p, int argc, const char **argv)
  46 {
  47         int status;
  48         struct stat st;
  49
  50         assert(p);
  51
  52         status = p->fn(argc, argv);
  53         if (status)
  54                 return status;
  55
  56         /* Somebody closed stdout? */
  57         if (fstat(fileno(stdout), &st))
  58                 return 0;
  59         /* Ignore write errors for pipes and sockets.. */
  60         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
  61                 return 0;
  62
  63         /* Check for ENOSPC and EIO errors.. */
  64         if (fflush(stdout)) {
  65                 perror("write failure on standard output");
  66                 return (errno);
  67         }
  68
  69         if (ferror(stdout)) {
  70                 perror("unknown write failure on standard output");
  71                 return (1);
  72         }
  73
  74         if (fclose(stdout)) {
  75                 perror("close failed on standard output");
  76                 return (errno);
  77         }
  78
  79         return 0;
  80 }
  81
  82 static int handle_internal_command(int argc, const char **argv)
  83 {
  84         size_t i;
  85         const char *cmd = argv[0];
  86         static struct cmd_struct commands[] = {
  87                 {"interface", cmd_interface},
  88                 {"capture", cmd_capture},
  89                 {"help", cmd_help}
  90         };
  91
  92         if (argc == 0 || cmd == NULL || !strcmp(cmd, "--help"))
  93                 cmd = "help";
  94
  95         /* Turn "dabba cmd --help" into "dabba help cmd" */
  96         if (argc > 1 && !strcmp(argv[1], "--help")) {
  97                 argv[1] = argv[0];
  98                 argv[0] = cmd = "help";
  99         }
 100
 101         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 102                 struct cmd_struct *p = commands + i;
 103                 if (strcmp(p->cmd, cmd))
 104                         continue;
 105
 106                 argc--;
 107                 argv++;
 108
 109                 return (run_builtin(p, argc, argv));
 110         }
 111
 112         help_unknown_cmd(cmd);
 113
 114         return ENOSYS;
 115 }
 116
 117 int main(int argc, const char **argv)
 118 {
 119         assert(argc);
 120         assert(argv);
 121
 122         argc--;
 123         argv++;
 124
 125         return (handle_internal_command(argc, argv));
 126 }