i-bash/builtins/ulimit.def

This file is ulimit.def, from which is created ulimit.c.
It implements the builtin "ulimit" in Bash.

Copyright (C) 1987, 1989, 1991 Free Software Foundation, Inc.

This file is part of GNU Bash, the Bourne Again SHell.

Bash is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

Bash is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with Bash; see the file COPYING.  If not, write to the Free Software
Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.

$PRODUCES ulimit.c

$BUILTIN ulimit
$FUNCTION ulimit_builtin
$DEPENDS_ON !_MINIX
$SHORT_DOC ulimit [-SHacdflmnpstuv] [limit]
Ulimit provides control over the resources available to processes
started by the shell, on systems that allow such control.  If an
option is given, it is interpreted as follows:

    -S	use the `soft' resource limit
    -H	use the `hard' resource limit
    -a	all current limits are reported
    -c	the maximum size of core files created
    -d	the maximum size of a process's data segment
    -f	the maximum size of files created by the shell
    -l	the maximum size a process may lock into memory
    -m	the maximum resident set size
    -n	the maximum number of open file descriptors
    -p	the pipe buffer size
    -s	the maximum stack size
    -t	the maximum amount of cpu time in seconds
    -u	the maximum number of user processes
    -v	the size of virtual memory 

If LIMIT is given, it is the new value of the specified resource;
the special LIMIT values `soft', `hard', and `unlimited' stand for
the current soft limit, the current hard limit, and no limit, respectively.
Otherwise, the current value of the specified resource is printed.
If no option is given, then -f is assumed.  Values are in 1024-byte
increments, except for -t, which is in seconds, -p, which is in
increments of 512 bytes, and -u, which is an unscaled number of
processes.
$END

#if !defined (_MINIX)

#include <config.h>

#include "../bashtypes.h"
#ifndef _MINIX
#  include <sys/param.h>
#endif

#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif

#include <stdio.h>
#include <errno.h>

#include "../shell.h"
#include "common.h"
#include "bashgetopt.h"
#include "pipesize.h"

#if !defined (errno)
extern int errno;
#endif

/* For some reason, HPUX chose to make these definitions visible only if
   _KERNEL is defined, so we define _KERNEL before including <sys/resource.h>
   and #undef it afterward. */
#if defined (HAVE_RESOURCE)
#  include <sys/time.h>
#  if defined (HPUX) && defined (RLIMIT_NEEDS_KERNEL)
#    define _KERNEL
#  endif
#  include <sys/resource.h>
#  if defined (HPUX) && defined (RLIMIT_NEEDS_KERNEL)
#    undef _KERNEL
#  endif
#else
#  include <sys/times.h>
#endif

#if defined (HAVE_LIMITS_H)
#  include <limits.h>
#endif

/* Check for the most basic symbols.  If they aren't present, this
   system's <sys/resource.h> isn't very useful to us. */
#if !defined (RLIMIT_FSIZE) || !defined (HAVE_GETRLIMIT)
#  undef HAVE_RESOURCE
#endif

#if !defined (RLIMTYPE)
#  define RLIMTYPE long
#  define string_to_rlimtype(s) strtol(s, (char **)NULL, 10)
#  define print_rlimtype(num, nl) printf ("%ld%s", num, nl ? "\n" : "")
#endif

/* Some systems use RLIMIT_NOFILE, others use RLIMIT_OFILE */
#if defined (HAVE_RESOURCE) && defined (RLIMIT_OFILE) && !defined (RLIMIT_NOFILE)
#  define RLIMIT_NOFILE RLIMIT_OFILE
#endif /* HAVE_RESOURCE && RLIMIT_OFILE && !RLIMIT_NOFILE */

/* Some systems have these, some do not. */
#ifdef RLIMIT_FSIZE
#  define RLIMIT_FILESIZE	RLIMIT_FSIZE
#else
#  define RLIMIT_FILESIZE	256
#endif

#define RLIMIT_PIPESIZE	257

#ifdef RLIMIT_NOFILE
#  define RLIMIT_OPENFILES	RLIMIT_NOFILE
#else
#  define RLIMIT_OPENFILES	258
#endif

#ifdef RLIMIT_VMEM
#  define RLIMIT_VIRTMEM	RLIMIT_VMEM
#  define RLIMIT_VMBLKSZ	1024
#else
#  ifdef RLIMIT_AS
#    define RLIMIT_VIRTMEM	RLIMIT_AS
#    define RLIMIT_VMBLKSZ	1024
#  else
#    define RLIMIT_VIRTMEM	259
#    define RLIMIT_VMBLKSZ	1
#  endif
#endif

#ifdef RLIMIT_NPROC
#  define RLIMIT_MAXUPROC	RLIMIT_NPROC
#else
#  define RLIMIT_MAXUPROC	260
#endif

#if !defined (RLIM_INFINITY)
#  define RLIM_INFINITY 0x7fffffff
#endif

#if !defined (RLIM_SAVED_CUR)
#  define RLIM_SAVED_CUR RLIM_INFINITY
#endif

#if !defined (RLIM_SAVED_MAX)
#  define RLIM_SAVED_MAX RLIM_INFINITY
#endif

#define LIMIT_HARD 0x01
#define LIMIT_SOFT 0x02

static int _findlim __P((int));

static int ulimit_internal __P((int, char *, int, int));

static int get_limit __P((int, RLIMTYPE *, RLIMTYPE *));
static int set_limit __P((int, RLIMTYPE, int));

static void printone __P((int, RLIMTYPE, int));
static void print_all_limits __P((int));

static int set_all_limits __P((int, RLIMTYPE));

static int filesize __P((RLIMTYPE *));
static int pipesize __P((RLIMTYPE *));
static int getmaxuprc __P((RLIMTYPE *));
static int getmaxvm __P((RLIMTYPE *, RLIMTYPE *));

typedef struct {
  int  option;			/* The ulimit option for this limit. */
  int  parameter;		/* Parameter to pass to get_limit (). */
  int  block_factor;		/* Blocking factor for specific limit. */
  char *description;		/* Descriptive string to output. */
  char *units;			/* scale */
} RESOURCE_LIMITS;

static RESOURCE_LIMITS limits[] = {
#ifdef RLIMIT_CORE
  { 'c',	RLIMIT_CORE,  1024,	"core file size",	"blocks" },
#endif
#ifdef RLIMIT_DATA
  { 'd',	RLIMIT_DATA,  1024,	"data seg size",	"kbytes" },
#endif
  { 'f',	RLIMIT_FILESIZE, 1024,	"file size",		"blocks" },
#ifdef RLIMIT_MEMLOCK
  { 'l',	RLIMIT_MEMLOCK, 1024,	"max locked memory",	"kbytes" },
#endif
#ifdef RLIMIT_RSS
  { 'm',	RLIMIT_RSS,   1024,	"max memory size",	"kbytes" },
#endif /* RLIMIT_RSS */
  { 'n',	RLIMIT_OPENFILES, 1,	"open files",		(char *)NULL},
  { 'p',	RLIMIT_PIPESIZE, 512,	"pipe size", 		"512 bytes" },
#ifdef RLIMIT_STACK
  { 's',	RLIMIT_STACK, 1024,	"stack size",		"kbytes" },
#endif
#ifdef RLIMIT_CPU
  { 't',	RLIMIT_CPU,      1,	"cpu time",		"seconds" },
#endif /* RLIMIT_CPU */
  { 'u',	RLIMIT_MAXUPROC, 1,	"max user processes",	(char *)NULL },
#if defined (HAVE_RESOURCE)
  { 'v',	RLIMIT_VIRTMEM, RLIMIT_VMBLKSZ, "virtual memory", "kbytes" },
#endif
#ifdef RLIMIT_SWAP
  { 'w',	RLIMIT_SWAP,	1024,	"swap size",		"kbytes" },
#endif
  { -1, -1, -1, (char *)NULL, (char *)NULL }
};
#define NCMDS	(sizeof(limits) / sizeof(limits[0]))

typedef struct _cmd {
  int cmd;
  char *arg;
} ULCMD;

static ULCMD *cmdlist;
static int ncmd;
static int cmdlistsz;

#if !defined (HAVE_RESOURCE) && !defined (HAVE_ULIMIT)
long
ulimit (cmd, newlim)
     int cmd;
     long newlim;
{
  errno = EINVAL;
  return -1;
}
#endif /* !HAVE_RESOURCE && !HAVE_ULIMIT */

static int
_findlim (opt)
     int opt;
{
  register int i;

  for (i = 0; limits[i].option > 0; i++)
    if (limits[i].option == opt)
      return i;
  return -1;
}

static char optstring[4 + 2 * NCMDS];

/* Report or set limits associated with certain per-process resources.
   See the help documentation in builtins.c for a full description. */
int
ulimit_builtin (list)
     register WORD_LIST *list;
{
  register char *s;
  int c, limind, mode, opt, all_limits;

  mode = 0;

  all_limits = 0;

  /* Idea stolen from pdksh -- build option string the first time called. */
  if (optstring[0] == 0)
    {
      s = optstring;
      *s++ = 'a'; *s++ = 'S'; *s++ = 'H';
      for (c = 0; limits[c].option > 0; c++)
	{
	  *s++ = limits[c].option;
	  *s++ = ';';
	}
      *s = '\0';
    }

  /* Initialize the command list. */
  if (cmdlistsz == 0)
    cmdlist = (ULCMD *)xmalloc ((cmdlistsz = 16) * sizeof (ULCMD));
  ncmd = 0;

  reset_internal_getopt ();
  while ((opt = internal_getopt (list, optstring)) != -1)
    {
      switch (opt)
	{
	case 'a':
	  all_limits++;
	  break;

	/* -S and -H are modifiers, not real options.  */
	case 'S':
	  mode |= LIMIT_SOFT;
	  break;

	case 'H':
	  mode |= LIMIT_HARD;
	  break;

	case '?':
	  builtin_usage ();
	  return (EX_USAGE);

	default:
	  if (ncmd >= cmdlistsz)
	    cmdlist = (ULCMD *)xrealloc (cmdlist, (cmdlistsz *= 2) * sizeof (ULCMD));
	  cmdlist[ncmd].cmd = opt;
	  cmdlist[ncmd++].arg = list_optarg;
	  break;
	}
    }
  list = loptend;

  if (all_limits)
    {
#ifdef NOTYET
      if (list)		/* setting */
        {
          if (STREQ (list->word->word, "unlimited") == 0)
            {
              builtin_error ("invalid limit argument: %s", list->word->word);
              return (EXECUTION_FAILURE);
            }
          return (set_all_limits (mode == 0 ? LIMIT_SOFT|LIMIT_HARD : mode, RLIM_INFINITY));
        }
#endif
      print_all_limits (mode == 0 ? LIMIT_SOFT : mode);
      return (EXECUTION_SUCCESS);
    }

  /* default is `ulimit -f' */
  if (ncmd == 0)
    {
      cmdlist[ncmd].cmd = 'f';
      /* `ulimit something' is same as `ulimit -f something' */
      cmdlist[ncmd++].arg = list ? list->word->word : (char *)NULL;
      if (list)
	list = list->next;
    }

  /* verify each command in the list. */
  for (c = 0; c < ncmd; c++)
    {
      limind = _findlim (cmdlist[c].cmd);
      if (limind == -1)
	{
	  builtin_error ("bad command: `%c'", cmdlist[c].cmd);
	  return (EX_USAGE);
	}
    }

  for (c = 0; c < ncmd; c++)
    if (ulimit_internal (cmdlist[c].cmd, cmdlist[c].arg, mode, ncmd > 1) == EXECUTION_FAILURE)
      return (EXECUTION_FAILURE);

  return (EXECUTION_SUCCESS);
}

static int
ulimit_internal (cmd, cmdarg, mode, multiple)
     int cmd;
     char *cmdarg;
     int mode, multiple;
{
  int opt, limind, setting;
  int block_factor;
  RLIMTYPE soft_limit, hard_limit, real_limit, limit;

  setting = cmdarg != 0;
  limind = _findlim (cmd);
  if (mode == 0)
    mode = setting ? (LIMIT_HARD|LIMIT_SOFT) : LIMIT_SOFT;
  opt = get_limit (limind, &soft_limit, &hard_limit);
  if (opt < 0)
    {
      builtin_error ("cannot get %s limit: %s", limits[limind].description,
						strerror (errno));
      return (EXECUTION_FAILURE);
    }

  if (setting == 0)	/* print the value of the specified limit */
    {
      printone (limind, (mode & LIMIT_SOFT) ? soft_limit : hard_limit, multiple);
      return (EXECUTION_SUCCESS);
    }
 
  /* Setting the limit. */
  if (STREQ (cmdarg, "hard"))
    real_limit = hard_limit;
  else if (STREQ (cmdarg, "soft"))
    real_limit = soft_limit;
  else if (STREQ (cmdarg, "unlimited"))
    real_limit = RLIM_INFINITY;
  else if (all_digits (cmdarg))
    {
      limit = string_to_rlimtype (cmdarg);
      block_factor = limits[limind].block_factor;
      real_limit = limit * block_factor;

      if ((real_limit / block_factor) != limit)
	{
	  builtin_error ("limit out of range: %s", cmdarg);
	  return (EXECUTION_FAILURE);
	}
    }
  else
    {
      builtin_error ("bad non-numeric arg `%s'", cmdarg);
      return (EXECUTION_FAILURE);
    }

  if (set_limit (limind, real_limit, mode) < 0)
    {
      builtin_error ("cannot modify %s limit: %s", limits[limind].description,
						   strerror (errno));
      return (EXECUTION_FAILURE);
    }

  return (EXECUTION_SUCCESS);
}

static int
get_limit (ind, softlim, hardlim)
     int ind;
     RLIMTYPE *softlim, *hardlim;
{
  RLIMTYPE value;
#if defined (HAVE_RESOURCE)
  struct rlimit limit;
#endif

  if (limits[ind].parameter >= 256)
    {
      switch (limits[ind].parameter)
	{
	case RLIMIT_FILESIZE:
	  if (filesize (&value) < 0)
	    return -1;
	  break;
	case RLIMIT_PIPESIZE:
	  if (pipesize (&value) < 0)
	    return -1;
	  break;
	case RLIMIT_OPENFILES:
	  value = (RLIMTYPE)getdtablesize ();
	  break;
	case RLIMIT_VIRTMEM:
	  return (getmaxvm (softlim, hardlim));
	case RLIMIT_MAXUPROC:
	  if (getmaxuprc (&value) < 0)
	    return -1;
	  break;
	default:
	  errno = EINVAL;
	  return -1;
	}
      *softlim = *hardlim = value;
      return (0);
    }
  else
    {
#if defined (HAVE_RESOURCE)
      if (getrlimit (limits[ind].parameter, &limit) < 0)
	return -1;
      *softlim = limit.rlim_cur;
      *hardlim = limit.rlim_max;
#  if defined (HPUX9)
      if (limits[ind].parameter == RLIMIT_FILESIZE)
	{
	  *softlim *= 512;
	  *hardlim *= 512;			/* Ugh. */
	}
      else
#  endif /* HPUX9 */
      return 0;
#else
      errno = EINVAL;
      return -1;
#endif
    }
}

static int
set_limit (ind, newlim, mode)
     int ind;
     RLIMTYPE newlim;
     int mode;
{
#if defined (HAVE_RESOURCE)
   struct rlimit limit;
   RLIMTYPE val;
#endif

  if (limits[ind].parameter >= 256)
    switch (limits[ind].parameter)
      {
      case RLIMIT_FILESIZE:
#if !defined (HAVE_RESOURCE)
	return (ulimit (2, newlim / 512L));
#else
	errno = EINVAL;
	return -1;
#endif

      case RLIMIT_OPENFILES:
#if defined (HAVE_SETDTABLESIZE)
#  if defined (__CYGWIN__)
	/* Grrr... Cygwin declares setdtablesize as void. */
	setdtablesize (newlim);
	return 0;
#  else
	return (setdtablesize (newlim));
#  endif
#endif
      case RLIMIT_PIPESIZE:
      case RLIMIT_VIRTMEM:
      case RLIMIT_MAXUPROC:
      default:
	errno = EINVAL;
	return -1;
      }
  else
    {
#if defined (HAVE_RESOURCE)
      if (getrlimit (limits[ind].parameter, &limit) < 0)
	return -1;
#  if defined (HPUX9)
      if (limits[ind].parameter == RLIMIT_FILESIZE)
	newlim /= 512;				/* Ugh. */
#  endif /* HPUX9 */
      val = (current_user.euid != 0 && newlim == RLIM_INFINITY &&
	       (mode & LIMIT_HARD) == 0 &&		/* XXX -- test */
	       (limit.rlim_cur <= limit.rlim_max))
		 ? limit.rlim_max : newlim;
      if (mode & LIMIT_SOFT)
	limit.rlim_cur = val;
      if (mode & LIMIT_HARD)
	limit.rlim_max = val;
	  
      return (setrlimit (limits[ind].parameter, &limit));
#else
      errno = EINVAL;
      return -1;
#endif
    }
}

static int
getmaxvm (softlim, hardlim)
     RLIMTYPE *softlim, *hardlim;
{
#if defined (HAVE_RESOURCE)
  struct rlimit datalim, stacklim;

  if (getrlimit (RLIMIT_DATA, &datalim) < 0)
    return -1;

  if (getrlimit (RLIMIT_STACK, &stacklim) < 0)
    return -1;

  /* Protect against overflow. */
  *softlim = (datalim.rlim_cur / 1024L) + (stacklim.rlim_cur / 1024L);
  *hardlim = (datalim.rlim_max / 1024L) + (stacklim.rlim_max / 1024L);
  return 0;
#else
  errno = EINVAL;
  return -1;
#endif /* HAVE_RESOURCE */
}

static int
filesize(valuep)
     RLIMTYPE *valuep;
{
#if !defined (HAVE_RESOURCE)
  long result;
  if ((result = ulimit (1, 0L)) < 0)
    return -1;
  else
    *valuep = (RLIMTYPE) result * 512;
  return 0;
#else
  errno = EINVAL;
  return -1;
#endif
}

static int
pipesize (valuep)
     RLIMTYPE *valuep;
{
#if defined (PIPE_BUF)
  /* This is defined on Posix systems. */
  *valuep = (RLIMTYPE) PIPE_BUF;
  return 0;
#else
#  if defined (PIPESIZE)
  /* This is defined by running a program from the Makefile. */
  *valuep = (RLIMTYPE) PIPESIZE;
  return 0;
#  else
  errno = EINVAL;
  return -1;  
#  endif /* PIPESIZE */
#endif /* PIPE_BUF */
}

static int
getmaxuprc (valuep)
     RLIMTYPE *valuep;
{
#  if defined (HAVE_SYSCONF) && defined (_SC_CHILD_MAX)
  long maxchild;
  maxchild = sysconf (_SC_CHILD_MAX);
  if (maxchild < 0)
    return -1;
  else
    *valuep = (RLIMTYPE) maxchild;
  return 0;
#  else /* !HAVE_SYSCONF || !_SC_CHILD_MAX */
#    if defined (MAXUPRC)
  *valuep = (RLIMTYPE) MAXUPRC;
  return 0;
#    else /* MAXUPRC */
  errno = EINVAL;
  return -1;
#    endif /* !MAXUPRC */
#  endif /* !HAVE_SYSCONF || !_SC_CHILD_MAX */
}

static void
print_all_limits (mode)
     int mode;
{
  register int i;
  RLIMTYPE softlim, hardlim;

  if (mode == 0)
    mode |= LIMIT_SOFT;

  for (i = 0; limits[i].option > 0; i++)
    {
      if (get_limit (i, &softlim, &hardlim) < 0)
	builtin_error ("cannot get %s limit: %s", limits[i].description, strerror (errno));
      else
	printone (i, (mode & LIMIT_SOFT) ? softlim : hardlim, 1);
    }
}

static void
printone (limind, curlim, pdesc)
     int limind;
     RLIMTYPE curlim;
     int pdesc;
{
  char unitstr[64];

  if (pdesc)
    {
      if (limits[limind].units)
	sprintf (unitstr, "(%s, -%c) ", limits[limind].units, limits[limind].option);
      else
        sprintf (unitstr, "(-%c) ", limits[limind].option);

      printf ("%-18s %16s", limits[limind].description, unitstr);
    }
  if (curlim == RLIM_INFINITY)
    puts ("unlimited");
  else if (curlim == RLIM_SAVED_MAX)
    puts ("hard");
  else if (curlim == RLIM_SAVED_CUR)
    puts ("soft");
  else
    print_rlimtype ((curlim / limits[limind].block_factor), 1);
}

/* Set all limits to NEWLIM.  NEWLIM currently must be RLIM_INFINITY, which
   causes all limits to be set as high as possible depending on mode (like
   csh `unlimit').  Returns -1 if NEWLIM is invalid, 0 if all limits
   were set successfully, and 1 if at least one limit could not be set.

   To raise all soft limits to their corresponding hard limits, use
	ulimit -S -a unlimited
   To attempt to raise all hard limits to infinity (superuser-only), use
	ulimit -H -a unlimited
   To attempt to raise all soft and hard limits to infinity, use
	ulimit -a unlimited
*/

static int
set_all_limits (mode, newlim)
     int mode;
     RLIMTYPE newlim;
{
  register int i;
  int retval = 0;

  if (newlim != RLIM_INFINITY)
    {
      errno = EINVAL;
      return -1;
    }
  
  if (mode == 0)
    mode = LIMIT_SOFT|LIMIT_HARD;

  for (retval = i = 0; limits[i].option > 0; i++)
    if (set_limit (i, newlim, mode) < 0)
      {
	builtin_error ("cannot modify %s limit: %s", limits[i].description,
						     strerror (errno));
	retval = 1;
      }
  return retval;
}

#endif /* !_MINIX */