libguile/simpos.c

   1 /*      Copyright (C) 1995,1996,1997,1998, 2000, 2001 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46
  47 #include <errno.h>
  48
  49 #include "libguile/_scm.h"
  50
  51 #include "libguile/scmsigs.h"
  52 #include "libguile/strings.h"
  53
  54 #include "libguile/validate.h"
  55 #include "libguile/simpos.h"
  56
  57 #ifdef HAVE_STRING_H
  58 #include <string.h>
  59 #endif
  60 #ifdef HAVE_UNISTD_H
  61 #include <unistd.h>
  62 #endif
  63
  64 \f
  65 extern int system();
  66 \f
  67
  68 #ifdef HAVE_SYSTEM
  69 SCM_DEFINE (scm_system, "system", 0, 1, 0,
  70            (SCM cmd),
  71             "Execute @var{cmd} using the operating system's \"command\n"
  72             "processor\".  Under Unix this is usually the default shell\n"
  73             "@code{sh}.  The value returned is @var{cmd}'s exit status as\n"
  74             "returned by @code{waitpid}, which can be interpreted using the\n"
  75             "functions above.\n"
  76             "\n"
  77             "If @code{system} is called without arguments, return a boolean\n"
  78             "indicating whether the command processor is available.")
  79 #define FUNC_NAME s_scm_system
  80 {
  81   int rv;
  82
  83   if (SCM_UNBNDP (cmd))
  84     {
  85       rv = system (NULL);
  86       return SCM_BOOL(rv);
  87     }
  88   SCM_VALIDATE_STRING (1, cmd);
  89   SCM_DEFER_INTS;
  90   errno = 0;
  91   SCM_STRING_COERCE_0TERMINATION_X (cmd);
  92   rv = system (SCM_STRING_CHARS (cmd));
  93   if (rv == -1 || (rv == 127 && errno != 0))
  94     SCM_SYSERROR;
  95   SCM_ALLOW_INTS;
  96   return SCM_MAKINUM (rv);
  97 }
  98 #undef FUNC_NAME
  99 #endif /* HAVE_SYSTEM */
 100
 101 extern char *getenv();
 102 SCM_DEFINE (scm_getenv, "getenv", 1, 0, 0,
 103             (SCM nam),
 104             "Looks up the string @var{name} in the current environment.  The return\n"
 105             "value is @code{#f} unless a string of the form @code{NAME=VALUE} is\n"
 106             "found, in which case the string @code{VALUE} is returned.")
 107 #define FUNC_NAME s_scm_getenv
 108 {
 109   char *val;
 110   SCM_VALIDATE_STRING (1, nam);
 111   SCM_STRING_COERCE_0TERMINATION_X (nam);
 112   val = getenv (SCM_STRING_CHARS (nam));
 113   return (val) ? scm_makfromstr(val, (size_t)strlen(val), 0) : SCM_BOOL_F;
 114 }
 115 #undef FUNC_NAME
 116
 117 /* simple exit, without unwinding the scheme stack or flushing ports.  */
 118 SCM_DEFINE (scm_primitive_exit, "primitive-exit", 0, 1, 0,
 119             (SCM status),
 120             "Terminate the current process without unwinding the Scheme stack.\n"
 121             "This is would typically be useful after a fork.  The exit status\n"
 122             "is @var{status} if supplied, otherwise zero.")
 123 #define FUNC_NAME s_scm_primitive_exit
 124 {
 125   int cstatus = 0;
 126   if (!SCM_UNBNDP (status))
 127     {
 128       SCM_VALIDATE_INUM (1,status);
 129       cstatus = SCM_INUM (status);
 130     }
 131   exit (cstatus);
 132 }
 133 #undef FUNC_NAME
 134
 135
 136 void
 137 scm_init_simpos ()
 138 {
 139 #ifndef SCM_MAGIC_SNARFER
 140 #include "libguile/simpos.x"
 141 #endif
 142 }
 143
 144
 145 /*
 146   Local Variables:
 147   c-file-style: "gnu"
 148   End:
 149 */