libgfortran/intrinsics/execute_command_line.c

   1 /* Implementation of the EXECUTE_COMMAND_LINE intrinsic.
   2    Copyright (C) 2009-2017 Free Software Foundation, Inc.
   3    Contributed by François-Xavier Coudert.
   4
   5 This file is part of the GNU Fortran runtime library (libgfortran).
   6
   7 Libgfortran is free software; you can redistribute it and/or modify it under
   8 the terms of the GNU General Public License as published by the Free
   9 Software Foundation; either version 3, or (at your option) any later
  10 version.
  11
  12 Libgfortran is distributed in the hope that it will be useful, but WITHOUT
  13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14 FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  15 for more details.
  16
  17 Under Section 7 of GPL version 3, you are granted additional
  18 permissions described in the GCC Runtime Library Exception, version
  19 3.1, as published by the Free Software Foundation.
  20
  21 You should have received a copy of the GNU General Public License and
  22 a copy of the GCC Runtime Library Exception along with this program;
  23 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24 <http://www.gnu.org/licenses/>.  */
  25
  26 #include "libgfortran.h"
  27 #include <string.h>
  28
  29 #ifdef HAVE_UNISTD_H
  30 #include <unistd.h>
  31 #endif
  32 #ifdef  HAVE_SYS_WAIT_H
  33 #include <sys/wait.h>
  34 #endif
  35
  36
  37 enum { EXEC_SYNCHRONOUS = -2, EXEC_NOERROR = 0, EXEC_SYSTEMFAILED,
  38        EXEC_CHILDFAILED, EXEC_INVALIDCOMMAND };
  39 static const char *cmdmsg_values[] =
  40   { "",
  41     "Termination status of the command-language interpreter cannot be obtained",
  42     "Execution of child process impossible",
  43     "Invalid command line" };
  44
  45
  46
  47 static void
  48 set_cmdstat (int *cmdstat, int value)
  49 {
  50   if (cmdstat)
  51     *cmdstat = value;
  52   else if (value > EXEC_NOERROR)
  53     {
  54 #define MSGLEN 200
  55       char msg[MSGLEN] = "EXECUTE_COMMAND_LINE: ";
  56       strncat (msg, cmdmsg_values[value], MSGLEN - strlen(msg) - 1);
  57       runtime_error ("%s", msg);
  58     }
  59 }
  60
  61
  62 static void
  63 execute_command_line (const char *command, bool wait, int *exitstat,
  64                       int *cmdstat, char *cmdmsg,
  65                       gfc_charlen_type command_len,
  66                       gfc_charlen_type cmdmsg_len)
  67 {
  68   /* Transform the Fortran string to a C string.  */
  69   char *cmd = fc_strdup (command, command_len);
  70
  71   /* Flush all I/O units before executing the command.  */
  72   flush_all_units();
  73
  74 #if defined(HAVE_FORK)
  75   if (!wait)
  76     {
  77       /* Asynchronous execution.  */
  78       pid_t pid;
  79
  80       set_cmdstat (cmdstat, EXEC_NOERROR);
  81
  82       if ((pid = fork()) < 0)
  83         set_cmdstat (cmdstat, EXEC_CHILDFAILED);
  84       else if (pid == 0)
  85         {
  86           /* Child process.  */
  87           int res = system (cmd);
  88           _exit (WIFEXITED(res) ? WEXITSTATUS(res) : res);
  89         }
  90     }
  91   else
  92 #endif
  93     {
  94       /* Synchronous execution.  */
  95       int res = system (cmd);
  96
  97       if (res == -1)
  98         set_cmdstat (cmdstat, EXEC_SYSTEMFAILED);
  99 #ifndef HAVE_FORK
 100       else if (!wait)
 101         set_cmdstat (cmdstat, EXEC_SYNCHRONOUS);
 102 #endif
 103       else if (res == 127 || res == 126
 104 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 105                || (WIFEXITED(res) && WEXITSTATUS(res) == 127)
 106                || (WIFEXITED(res) && WEXITSTATUS(res) == 126)
 107 #endif
 108                )
 109         /* Shell return codes 126 and 127 mean that the command line could
 110            not be executed for various reasons.  */
 111         set_cmdstat (cmdstat, EXEC_INVALIDCOMMAND);
 112       else
 113         set_cmdstat (cmdstat, EXEC_NOERROR);
 114
 115       if (res != -1)
 116         {
 117 #if defined(WEXITSTATUS) && defined(WIFEXITED)
 118           *exitstat = WIFEXITED(res) ? WEXITSTATUS(res) : res;
 119 #else
 120           *exitstat = res;
 121 #endif
 122         }
 123     }
 124
 125   free (cmd);
 126
 127   /* Now copy back to the Fortran string if needed.  */
 128   if (cmdstat && *cmdstat > EXEC_NOERROR)
 129     {
 130       if (cmdmsg)
 131         fstrcpy (cmdmsg, cmdmsg_len, cmdmsg_values[*cmdstat],
 132                 strlen (cmdmsg_values[*cmdstat]));
 133       else
 134         runtime_error ("Failure in EXECUTE_COMMAND_LINE: %s",
 135                        cmdmsg_values[*cmdstat]);
 136     }
 137 }
 138
 139
 140 extern void
 141 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait,
 142                          GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat,
 143                          char *cmdmsg, gfc_charlen_type command_len,
 144                          gfc_charlen_type cmdmsg_len);
 145 export_proto(execute_command_line_i4);
 146
 147 void
 148 execute_command_line_i4 (const char *command, GFC_LOGICAL_4 *wait,
 149                          GFC_INTEGER_4 *exitstat, GFC_INTEGER_4 *cmdstat,
 150                          char *cmdmsg, gfc_charlen_type command_len,
 151                          gfc_charlen_type cmdmsg_len)
 152 {
 153   bool w = wait ? *wait : true;
 154   int estat, estat_initial, cstat;
 155
 156   if (exitstat)
 157     estat_initial = estat = *exitstat;
 158
 159   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 160                         cmdmsg, command_len, cmdmsg_len);
 161
 162   if (exitstat && estat != estat_initial)
 163     *exitstat = estat;
 164   if (cmdstat)
 165     *cmdstat = cstat;
 166 }
 167
 168
 169 extern void
 170 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait,
 171                          GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat,
 172                          char *cmdmsg, gfc_charlen_type command_len,
 173                          gfc_charlen_type cmdmsg_len);
 174 export_proto(execute_command_line_i8);
 175
 176 void
 177 execute_command_line_i8 (const char *command, GFC_LOGICAL_8 *wait,
 178                          GFC_INTEGER_8 *exitstat, GFC_INTEGER_8 *cmdstat,
 179                          char *cmdmsg, gfc_charlen_type command_len,
 180                          gfc_charlen_type cmdmsg_len)
 181 {
 182   bool w = wait ? *wait : true;
 183   int estat, estat_initial, cstat;
 184
 185   if (exitstat)
 186     estat_initial = estat = *exitstat;
 187
 188   execute_command_line (command, w, &estat, cmdstat ? &cstat : NULL,
 189                         cmdmsg, command_len, cmdmsg_len);
 190
 191   if (exitstat && estat != estat_initial)
 192     *exitstat = estat;
 193   if (cmdstat)
 194     *cmdstat = cstat;
 195 }