xapian-core/tests/perftest/runprocess.cc

   1 /** @file
   2  * @brief run an external process and capture its output in a string.
   3  */
   4 /* Copyright (C) 2003,2006,2007 Olly Betts
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  19  */
  20
  21 #include <config.h>
  22
  23 #include "runprocess.h"
  24 #include "stringutils.h"
  25
  26 #include <stdio.h>
  27 #include <string>
  28
  29 #include "safesyswait.h"
  30
  31 #ifdef _MSC_VER
  32 # define popen _popen
  33 # define pclose _pclose
  34 #endif
  35
  36 using namespace std;
  37
  38 string
  39 stdout_to_string(const string &cmd)
  40 {
  41     string out;
  42     FILE * fh = popen(cmd.c_str(), "r");
  43     if (fh == NULL) throw ReadError();
  44     while (!feof(fh)) {
  45         char buf[4096];
  46         size_t len = fread(buf, 1, 4096, fh);
  47         if (ferror(fh)) {
  48             (void)pclose(fh);
  49             throw ReadError();
  50         }
  51         out.append(buf, len);
  52     }
  53     int status = pclose(fh);
  54
  55     if (status != 0) {
  56         if (WIFEXITED(status) && WEXITSTATUS(status) == 127) {
  57             throw NoSuchProgram();
  58         }
  59         throw ReadError();
  60     }
  61     while (out.size() > 0 && C_isspace(out[out.size() - 1])) {
  62         out.resize(out.size() - 1);
  63     }
  64     return out;
  65 }