src/port/system.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * system.c
   4  *         Win32 system() and popen() replacements
   5  *
   6  *
   7  *      Win32 needs double quotes at the beginning and end of system()
   8  *      strings.  If not, it gets confused with multiple quoted strings.
   9  *      It also requires double-quotes around the executable name and
  10  *      any files used for redirection.  Filter other args through
  11  *      appendShellString() to quote them.
  12  *
  13  *      Generated using Win32 "CMD /?":
  14  *
  15  *      1. If all of the following conditions are met, then quote characters
  16  *      on the command line are preserved:
  17  *
  18  *       - no /S switch
  19  *       - exactly two quote characters
  20  *       - no special characters between the two quote characters, where special
  21  *         is one of: &<>()@^|
  22  *       - there are one or more whitespace characters between the two quote
  23  *         characters
  24  *       - the string between the two quote characters is the name of an
  25  *         executable file.
  26  *
  27  *       2. Otherwise, old behavior is to see if the first character is a quote
  28  *       character and if so, strip the leading character and remove the last
  29  *       quote character on the command line, preserving any text after the last
  30  *       quote character.
  31  *
  32  * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
  33  *
  34  * src/port/system.c
  35  *
  36  *-------------------------------------------------------------------------
  37  */
  38
  39 #if defined(WIN32) && !defined(__CYGWIN__)
  40
  41 #ifndef FRONTEND
  42 #include "postgres.h"
  43 #else
  44 #include "postgres_fe.h"
  45 #endif
  46
  47 #include <fcntl.h>
  48
  49 #undef system
  50 #undef popen
  51
  52 int
  53 pgwin32_system(const char *command)
  54 {
  55         size_t          cmdlen = strlen(command);
  56         char       *buf;
  57         int                     save_errno;
  58         int                     res;
  59
  60         /*
  61          * Create a malloc'd copy of the command string, enclosed with an extra
  62          * pair of quotes
  63          */
  64         buf = malloc(cmdlen + 2 + 1);
  65         if (buf == NULL)
  66         {
  67                 errno = ENOMEM;
  68                 return -1;
  69         }
  70         buf[0] = '"';
  71         memcpy(&buf[1], command, cmdlen);
  72         buf[cmdlen + 1] = '"';
  73         buf[cmdlen + 2] = '\0';
  74
  75         res = system(buf);
  76
  77         save_errno = errno;
  78         free(buf);
  79         errno = save_errno;
  80
  81         return res;
  82 }
  83
  84
  85 FILE *
  86 pgwin32_popen(const char *command, const char *type)
  87 {
  88         size_t          cmdlen = strlen(command);
  89         char       *buf;
  90         int                     save_errno;
  91         FILE       *res;
  92
  93         /*
  94          * Create a malloc'd copy of the command string, enclosed with an extra
  95          * pair of quotes
  96          */
  97         buf = malloc(cmdlen + 2 + 1);
  98         if (buf == NULL)
  99         {
 100                 errno = ENOMEM;
 101                 return NULL;
 102         }
 103         buf[0] = '"';
 104         memcpy(&buf[1], command, cmdlen);
 105         buf[cmdlen + 1] = '"';
 106         buf[cmdlen + 2] = '\0';
 107
 108         res = _popen(buf, type);
 109
 110         save_errno = errno;
 111         free(buf);
 112         errno = save_errno;
 113
 114         return res;
 115 }
 116
 117 #endif