c_ulimit.c

一个开放源代码的 AT&T 的 Korn Shell 的复制品, 支持大多数 ksh89 的特性。

/*
	ulimit -- handle "ulimit" builtin

	Reworked to use getrusage() and ulimit() at once (as needed on
	some schizophenic systems, eg, HP-UX 9.01), made argument parsing
	conform to at&t ksh, added autoconf support.  Michael Rendell, May, '94

	Eric Gisin, September 1988
	Adapted to PD KornShell. Removed AT&T code.

	last edit:	06-Jun-1987	D A Gwyn

	This started out as the BRL UNIX System V system call emulation
	for 4.nBSD, and was later extended by Doug Kingston to handle
	the extended 4.nBSD resource limits.  It now includes the code
	that was originally under case SYSULIMIT in source file "xec.c".
*/

#include "sh.h"
#include "ksh_time.h"
#ifdef HAVE_SYS_RESOURCE_H
# include <sys/resource.h>
#endif /* HAVE_SYS_RESOURCE_H */
#ifdef HAVE_ULIMIT_H
# include <ulimit.h>
#else /* HAVE_ULIMIT_H */
# ifdef HAVE_ULIMIT
extern	long ulimit();
# endif /* HAVE_ULIMIT */
#endif /* HAVE_ULIMIT_H */

#define SOFT	0x1
#define HARD	0x2

#ifdef RLIM_INFINITY
# define KSH_RLIM_INFINITY RLIM_INFINITY
#else
# define KSH_RLIM_INFINITY ((rlim_t) 1 << (sizeof(rlim_t) * 8 - 1) - 1)
#endif /* RLIM_INFINITY */

int
c_ulimit(wp)
	char **wp;
{
	static const struct limits {
		const char	*name;
		enum { RLIMIT, ULIMIT } which;
		int	gcmd;	/* get command */
		int	scmd;	/* set command (or -1, if no set command) */
		int	factor;	/* multiply by to get rlim_{cur,max} values */
		char	option;
	} limits[] = {
		/* Do not use options -H, -S or -a */
#ifdef RLIMIT_CPU
		{ "time(cpu-seconds)", RLIMIT, RLIMIT_CPU, RLIMIT_CPU, 1, 't' },
#endif
#ifdef RLIMIT_FSIZE
		{ "file(blocks)", RLIMIT, RLIMIT_FSIZE, RLIMIT_FSIZE, 512, 'f' },
#else /* RLIMIT_FSIZE */
# ifdef UL_GETFSIZE /* x/open */
		{ "file(blocks)", ULIMIT, UL_GETFSIZE, UL_SETFSIZE, 1, 'f' },
# else /* UL_GETFSIZE */
#  ifdef UL_GFILLIM /* svr4/xenix */
		{ "file(blocks)", ULIMIT, UL_GFILLIM, UL_SFILLIM, 1, 'f' },
#  else /* UL_GFILLIM */
		{ "file(blocks)", ULIMIT, 1, 2, 1, 'f' },
#  endif /* UL_GFILLIM */
# endif /* UL_GETFSIZE */
#endif /* RLIMIT_FSIZE */
#ifdef RLIMIT_CORE
		{ "coredump(blocks)", RLIMIT, RLIMIT_CORE, RLIMIT_CORE, 512, 'c' },
#endif
#ifdef RLIMIT_DATA
		{ "data(kbytes)", RLIMIT, RLIMIT_DATA, RLIMIT_DATA, 1024, 'd' },
#endif
#ifdef RLIMIT_STACK
		{ "stack(kbytes)", RLIMIT, RLIMIT_STACK, RLIMIT_STACK, 1024, 's' },
#endif
#ifdef RLIMIT_MEMLOCK
		{ "lockedmem(kbytes)", RLIMIT, RLIMIT_MEMLOCK, RLIMIT_MEMLOCK, 1024, 'l' },
#endif
#ifdef RLIMIT_RSS
		{ "memory(kbytes)", RLIMIT, RLIMIT_RSS, RLIMIT_RSS, 1024, 'm' },
#endif
#ifdef RLIMIT_NOFILE
		{ "nofiles(descriptors)", RLIMIT, RLIMIT_NOFILE, RLIMIT_NOFILE, 1, 'n' },
#else /* RLIMIT_NOFILE */
# ifdef UL_GDESLIM /* svr4/xenix */
		{ "nofiles(descriptors)", ULIMIT, UL_GDESLIM, -1, 1, 'n' },
# endif /* UL_GDESLIM */
#endif /* RLIMIT_NOFILE */
#ifdef RLIMIT_NPROC
		{ "processes", RLIMIT, RLIMIT_NPROC, RLIMIT_NPROC, 1, 'p' },
#endif
#ifdef RLIMIT_VMEM
		{ "vmemory(kbytes)", RLIMIT, RLIMIT_VMEM, RLIMIT_VMEM, 1024, 'v' },
#else /* RLIMIT_VMEM */
  /* These are not quite right - really should subtract etext or something */
# ifdef UL_GMEMLIM /* svr4/xenix */
		{ "vmemory(maxaddr)", ULIMIT, UL_GMEMLIM, -1, 1, 'v' },
# else /* UL_GMEMLIM */
#  ifdef UL_GETBREAK /* osf/1 */
		{ "vmemory(maxaddr)", ULIMIT, UL_GETBREAK, -1, 1, 'v' },
#  else /* UL_GETBREAK */
#   ifdef UL_GETMAXBRK /* hpux */
		{ "vmemory(maxaddr)", ULIMIT, UL_GETMAXBRK, -1, 1, 'v' },
#   endif /* UL_GETMAXBRK */
#  endif /* UL_GETBREAK */
# endif /* UL_GMEMLIM */
#endif /* RLIMIT_VMEM */
#ifdef RLIMIT_SWAP
		{ "swap(kbytes)", RLIMIT_SWAP, RLIMIT_SWAP, 1024, 'w' },
#endif
		{ (char *) 0 }
	    };
	static char	options[3 + NELEM(limits)];
	rlim_t		UNINITIALIZED(val);
	int		how = SOFT | HARD;
	const struct limits	*l;
	int		set, all = 0;
	int		optc, what;
#ifdef HAVE_SETRLIMIT
	struct rlimit	limit;
#endif /* HAVE_SETRLIMIT */

	if (!options[0]) {
		/* build options string on first call - yuck */
		char *p = options;

		*p++ = 'H'; *p++ = 'S'; *p++ = 'a';
		for (l = limits; l->name; l++)
			*p++ = l->option;
		*p = '\0';
	}
	what = 'f';
	while ((optc = ksh_getopt(wp, &builtin_opt, options)) != EOF)
		switch (optc) {
		  case 'H':
			how = HARD;
			break;
		  case 'S':
			how = SOFT;
			break;
		  case 'a':
			all = 1;
			break;
		  case '?':
			return 1;
		  default:
			what = optc;
		}

	for (l = limits; l->name && l->option != what; l++)
		;
	if (!l->name) {
		internal_errorf(0, "ulimit: %c", what);
		return 1;
	}

	wp += builtin_opt.optind;
	set = *wp ? 1 : 0;
	if (set) {
		if (all || wp[1]) {
			bi_errorf("too many arguments");
			return 1;
		}
		if (strcmp(wp[0], "unlimited") == 0)
			val = KSH_RLIM_INFINITY;
		else {
			long rval;

			if (!evaluate(wp[0], &rval, KSH_RETURN_ERROR))
				return 1;
			/* Avoid problems caused by typos that
			 * evaluate misses due to evaluating unset
			 * parameters to 0...
			 * If this causes problems, will have to
			 * add parameter to evaluate() to control
			 * if unset params are 0 or an error.
			 */
			if (!rval && !digit(wp[0][0])) {
			    bi_errorf("invalid limit: %s", wp[0]);
			    return 1;
			}
			val = rval * l->factor;
		}
	}
	if (all) {
		for (l = limits; l->name; l++) {
#ifdef HAVE_SETRLIMIT
			if (l->which == RLIMIT) {
				getrlimit(l->gcmd, &limit);
				if (how & SOFT)
					val = limit.rlim_cur;
				else if (how & HARD)
					val = limit.rlim_max;
			} else 
#endif /* HAVE_SETRLIMIT */
#ifdef HAVE_ULIMIT
			{
				val = ulimit(l->gcmd, (rlim_t) 0);
			}
#else /* HAVE_ULIMIT */
				;
#endif /* HAVE_ULIMIT */
			shprintf("%-20s ", l->name);
#ifdef RLIM_INFINITY
			if (val == RLIM_INFINITY)
				shprintf("unlimited\n");
			else
#endif /* RLIM_INFINITY */
			{
				val /= l->factor;
				shprintf("%ld\n", (long) val);
			}
		}
		return 0;
	}
#ifdef HAVE_SETRLIMIT
	if (l->which == RLIMIT) {
		getrlimit(l->gcmd, &limit);
		if (set) {
			if (how & SOFT)
				limit.rlim_cur = val;
			if (how & HARD)
				limit.rlim_max = val;
			if (setrlimit(l->scmd, &limit) < 0) {
				if (errno == EPERM)
					bi_errorf("exceeds allowable limit");
				else
					bi_errorf("bad limit: %s",
						strerror(errno));
				return 1;
			}
		} else {
			if (how & SOFT)
				val = limit.rlim_cur;
			else if (how & HARD)
				val = limit.rlim_max;
		}
	} else
#endif /* HAVE_SETRLIMIT */
#ifdef HAVE_ULIMIT
	{
		if (set) {
			if (l->scmd == -1) {
				bi_errorf("can't change limit");
				return 1;
			} else if (ulimit(l->scmd, val) < 0) {
				bi_errorf("bad limit: %s", strerror(errno));
				return 1;
			}
		} else
			val = ulimit(l->gcmd, (rlim_t) 0);
	}
#else /* HAVE_ULIMIT */
		;
#endif /* HAVE_ULIMIT */
	if (!set) {
#ifdef RLIM_INFINITY
		if (val == RLIM_INFINITY)
			shprintf("unlimited\n");
		else
#endif /* RLIM_INFINITY */
		{
			val /= l->factor;
			shprintf("%ld\n", (long) val);
		}
	}
	return 0;
}