limits.c revision 169177 
1/*-
2 * Copyright (c) 1997 by
3 * David L. Nugent <davidn@blaze.net.au>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, is permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice immediately at the beginning of the file, without modification,
11 *    this list of conditions, and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. This work was done expressly for inclusion into FreeBSD.  Other use
16 *    is permitted provided this notation is included.
17 * 4. Absolutely no warranty of function or purpose is made by the authors.
18 * 5. Modifications may be freely made to this file providing the above
19 *    conditions are met.
20 *
21 * Display/change(+runprogram)/eval resource limits.
22 */
23
24#include <sys/cdefs.h>
25__FBSDID("$FreeBSD: head/usr.bin/limits/limits.c 169177 2007-05-01 16:02:44Z ache $");
26
27#include <err.h>
28#include <stdio.h>
29#include <string.h>
30#include <sys/types.h>
31#include <sys/stat.h>
32#include <sys/param.h>
33#include <stdlib.h>
34#include <unistd.h>
35#include <stdarg.h>
36#include <stdint.h>
37#include <ctype.h>
38#include <errno.h>
39#include <pwd.h>
40#include <login_cap.h>
41#include <sys/time.h>
42#include <sys/resource.h>
43
44enum
45{
46    SH_NONE,
47    SH_SH,      /* sh */
48    SH_CSH,     /* csh */
49    SH_BASH,    /* gnu bash */
50    SH_TCSH,    /* tcsh */
51    SH_KSH,     /* (pd)ksh */
52    SH_ZSH,     /* zsh */
53    SH_RC,      /* rc or es */
54    SH_NUMBER
55};
56
57
58/* eval emitter for popular shells.
59 * Why aren't there any standards here? Most shells support either
60 * the csh 'limit' or sh 'ulimit' command, but each varies just
61 * enough that they aren't very compatible from one to the other.
62 */
63static struct {
64    const char * name;	    /* Name of shell */
65    const char * inf;	    /* Name used for 'unlimited' resource */
66    const char * cmd;	    /* Intro text */
67    const char * hard;	    /* Hard limit text */
68    const char * soft;	    /* Soft limit text */
69    const char * both;	    /* Hard+Soft limit text */
70    struct {
71	const char * pfx;
72	const char * sfx;
73	int divisor;
74    } lprm[RLIM_NLIMITS];
75} shellparm[] =
76{
77    { "", "infinity", "Resource limits%s%s:\n", "-max", "-cur", "",
78      {
79	  { "  cputime%-4s      %8s", " secs\n",  1    },
80	  { "  filesize%-4s     %8s", " kB\n",    1024 },
81	  { "  datasize%-4s     %8s", " kB\n",    1024 },
82	  { "  stacksize%-4s    %8s", " kB\n",    1024 },
83	  { "  coredumpsize%-4s %8s", " kB\n",    1024 },
84	  { "  memoryuse%-4s    %8s", " kB\n",    1024 },
85	  { "  memorylocked%-4s %8s", " kB\n",    1024 },
86	  { "  maxprocesses%-4s %8s", "\n",       1    },
87	  { "  openfiles%-4s    %8s", "\n",       1    },
88	  { "  sbsize%-4s       %8s", " bytes\n", 1    },
89	  { "  vmemoryuse%-4s   %8s", " kB\n",    1024 }
90      }
91    },
92    { "sh", "unlimited", "", " -H", " -S", "",
93      {
94	  { "ulimit%s -t %s", ";\n",  1    },
95	  { "ulimit%s -f %s", ";\n",  512  },
96	  { "ulimit%s -d %s", ";\n",  1024 },
97	  { "ulimit%s -s %s", ";\n",  1024 },
98	  { "ulimit%s -c %s", ";\n",  512  },
99	  { "ulimit%s -m %s", ";\n",  1024 },
100	  { "ulimit%s -l %s", ";\n",  1024 },
101	  { "ulimit%s -u %s", ";\n",  1    },
102	  { "ulimit%s -n %s", ";\n",  1    },
103	  { "ulimit%s -b %s", ";\n",  1    },
104	  { "ulimit%s -v %s", ";\n",  1024 }
105      }
106    },
107    { "csh", "unlimited", "", " -h", "", NULL,
108      {
109	  { "limit%s cputime %s",      ";\n",  1    },
110	  { "limit%s filesize %s",     ";\n",  1024 },
111	  { "limit%s datasize %s",     ";\n",  1024 },
112	  { "limit%s stacksize %s",    ";\n",  1024 },
113	  { "limit%s coredumpsize %s", ";\n",  1024 },
114	  { "limit%s memoryuse %s",    ";\n",  1024 },
115	  { "limit%s memorylocked %s", ";\n",  1024 },
116	  { "limit%s maxproc %s",      ";\n",  1    },
117	  { "limit%s openfiles %s",    ";\n",  1    },
118	  { "limit%s sbsize %s",       ";\n",  1    },
119	  { "limit%s vmemoryuse %s",   ";\n",  1024 }
120      }
121    },
122    { "bash|bash2", "unlimited", "", " -H", " -S", "",
123      {
124	  { "ulimit%s -t %s", ";\n",  1    },
125	  { "ulimit%s -f %s", ";\n",  1024 },
126	  { "ulimit%s -d %s", ";\n",  1024 },
127	  { "ulimit%s -s %s", ";\n",  1024 },
128	  { "ulimit%s -c %s", ";\n",  1024 },
129	  { "ulimit%s -m %s", ";\n",  1024 },
130	  { "ulimit%s -l %s", ";\n",  1024 },
131	  { "ulimit%s -u %s", ";\n",  1    },
132	  { "ulimit%s -n %s", ";\n",  1    },
133	  { "ulimit%s -b %s", ";\n",  1    },
134	  { "ulimit%s -v %s", ";\n",  1024 }
135      }
136    },
137    { "tcsh", "unlimited", "", " -h", "", NULL,
138      {
139	  { "limit%s cputime %s",      ";\n",  1    },
140	  { "limit%s filesize %s",     ";\n",  1024 },
141	  { "limit%s datasize %s",     ";\n",  1024 },
142	  { "limit%s stacksize %s",    ";\n",  1024 },
143	  { "limit%s coredumpsize %s", ";\n",  1024 },
144	  { "limit%s memoryuse %s",    ";\n",  1024 },
145	  { "limit%s memorylocked %s", ";\n",  1024 },
146	  { "limit%s maxproc %s",      ";\n",  1    },
147	  { "limit%s descriptors %s",  ";\n",  1    },
148	  { "limit%s sbsize %s",       ";\n",  1    },
149	  { "limit%s vmemoryuse %s",   ";\n",  1024 }
150      }
151    },
152    { "ksh|pdksh", "unlimited", "", " -H", " -S", "",
153      {
154	  { "ulimit%s -t %s", ";\n",  1    },
155	  { "ulimit%s -f %s", ";\n",  512  },
156	  { "ulimit%s -d %s", ";\n",  1024 },
157	  { "ulimit%s -s %s", ";\n",  1024 },
158	  { "ulimit%s -c %s", ";\n",  512  },
159	  { "ulimit%s -m %s", ";\n",  1024 },
160	  { "ulimit%s -l %s", ";\n",  1024 },
161	  { "ulimit%s -p %s", ";\n",  1    },
162	  { "ulimit%s -n %s", ";\n",  1    },
163	  { "ulimit%s -b %s", ";\n",  1    },
164	  { "ulimit%s -v %s", ";\n",  1024 }
165      }
166    },
167    { "zsh", "unlimited", "", " -H", " -S", "",
168      {
169	  { "ulimit%s -t %s", ";\n",  1    },
170	  { "ulimit%s -f %s", ";\n",  512  },
171	  { "ulimit%s -d %s", ";\n",  1024 },
172	  { "ulimit%s -s %s", ";\n",  1024 },
173	  { "ulimit%s -c %s", ";\n",  512  },
174	  { "ulimit%s -m %s", ";\n",  1024 },
175	  { "ulimit%s -l %s", ";\n",  1024 },
176	  { "ulimit%s -u %s", ";\n",  1    },
177	  { "ulimit%s -n %s", ";\n",  1    },
178	  { "ulimit%s -b %s", ";\n",  1    },
179	  { "ulimit%s -v %s", ";\n",  1024 }
180      }
181    },
182    { "rc|es", "unlimited", "", " -h", "", NULL,
183      {
184	  { "limit%s cputime %s",      ";\n",  1    },
185	  { "limit%s filesize %s",     ";\n",  1024 },
186	  { "limit%s datasize %s",     ";\n",  1024 },
187	  { "limit%s stacksize %s",    ";\n",  1024 },
188	  { "limit%s coredumpsize %s", ";\n",  1024 },
189	  { "limit%s memoryuse %s",    ";\n",  1024 },
190	  { "limit%s lockedmemory %s", ";\n",  1024 },
191	  { "limit%s processes %s",    ";\n",  1    },
192	  { "limit%s descriptors %s",  ";\n",  1    },
193	  { "limit%s sbsize %s",       ";\n",  1    },
194	  { "limit%s vmemoryuse %s",   ";\n",  1024 }
195      }
196    },
197    { NULL, NULL, NULL, NULL, NULL, NULL,
198      { }
199    }
200};
201
202static struct {
203    const char * cap;
204    rlim_t (*func)(login_cap_t *, const char *, rlim_t, rlim_t);
205} resources[RLIM_NLIMITS] = {
206    { "cputime",	login_getcaptime },
207    { "filesize",	login_getcapsize },
208    { "datasize",	login_getcapsize },
209    { "stacksize",	login_getcapsize },
210    { "coredumpsize",	login_getcapsize },
211    { "memoryuse",	login_getcapsize },
212    { "memorylocked",	login_getcapsize },
213    { "maxproc",	login_getcapnum  },
214    { "openfiles",	login_getcapnum  },
215    { "sbsize",		login_getcapsize  },
216    { "vmemoryuse",	login_getcapsize  }
217};
218
219/*
220 * One letter for each resource levels.
221 * NOTE: There is a dependancy on the corresponding
222 * letter index being equal to the resource number.
223 * If sys/resource.h defines are changed, this needs
224 * to be modified accordingly!
225 */
226
227#define RCS_STRING  "tfdscmlunbv"
228
229static rlim_t resource_num(int which, int ch, const char *str);
230static void usage(void);
231static int getshelltype(void);
232static void print_limit(rlim_t limit, unsigned divisor, const char *inf,
233			const char *pfx, const char *sfx, const char *which);
234extern char **environ;
235
236static const char rcs_string[] = RCS_STRING;
237
238int
239main(int argc, char *argv[])
240{
241    char *p, *cls = NULL;
242    char *cleanenv[1];
243    struct passwd * pwd = NULL;
244    int rcswhich, shelltype;
245    int i, num_limits = 0;
246    int ch, doeval = 0, doall = 0;
247    login_cap_t * lc = NULL;
248    enum { ANY=0, SOFT=1, HARD=2, BOTH=3, DISPLAYONLY=4 } type = ANY;
249    enum { RCSUNKNOWN=0, RCSSET=1, RCSSEL=2 } todo = RCSUNKNOWN;
250    int which_limits[RLIM_NLIMITS];
251    rlim_t set_limits[RLIM_NLIMITS];
252    struct rlimit limits[RLIM_NLIMITS];
253
254    /* init resource tables */
255    for (i = 0; i < RLIM_NLIMITS; i++) {
256	which_limits[i] = 0; /* Don't set/display any */
257	set_limits[i] = RLIM_INFINITY;
258	/* Get current resource values */
259	getrlimit(i, &limits[i]);
260    }
261
262    optarg = NULL;
263    while ((ch = getopt(argc, argv, ":EeC:U:BSHab:c:d:f:l:m:n:s:t:u:v:")) != -1) {
264	switch(ch) {
265	case 'a':
266	    doall = 1;
267	    break;
268	case 'E':
269	    environ = cleanenv;
270	    cleanenv[0] = NULL;
271	    break;
272	case 'e':
273	    doeval = 1;
274	    break;
275	case 'C':
276	    cls = optarg;
277	    break;
278	case 'U':
279	    if ((pwd = getpwnam(optarg)) == NULL) {
280		if (!isdigit(*optarg) ||
281		    (pwd = getpwuid(atoi(optarg))) == NULL) {
282		    warnx("invalid user `%s'", optarg);
283		    usage();
284		}
285	    }
286	    break;
287	case 'H':
288	    type = HARD;
289	    break;
290	case 'S':
291	    type = SOFT;
292	    break;
293	case 'B':
294	    type = SOFT|HARD;
295	    break;
296	default:
297	case ':': /* Without arg */
298	    if ((p = strchr(rcs_string, optopt)) != NULL) {
299		int rcswhich1 = p - rcs_string;
300		if (optarg && *optarg == '-') { /* 'arg' is actually a switch */
301		    --optind;		/* back one arg, and make arg NULL */
302		    optarg = NULL;
303		}
304		todo = optarg == NULL ? RCSSEL : RCSSET;
305		if (type == ANY)
306		    type = BOTH;
307		which_limits[rcswhich1] = optarg ? type : DISPLAYONLY;
308		set_limits[rcswhich1] = resource_num(rcswhich1, optopt, optarg);
309		num_limits++;
310		break;
311	    }
312	    /* FALLTHRU */
313	case '?':
314	    usage();
315	}
316	optarg = NULL;
317    }
318
319    /* If user was specified, get class from that */
320    if (pwd != NULL)
321	lc = login_getpwclass(pwd);
322    else if (cls != NULL && *cls != '\0') {
323	lc = login_getclassbyname(cls, NULL);
324	if (lc == NULL || strcmp(cls, lc->lc_class) != 0)
325	    fprintf(stderr, "login class '%s' non-existent, using %s\n",
326		    cls, lc?lc->lc_class:"current settings");
327    }
328
329    /* If we have a login class, update resource table from that */
330    if (lc != NULL) {
331	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
332	    char str[40];
333	    rlim_t val;
334
335	    /* current value overridden by resourcename or resourcename-cur */
336	    sprintf(str, "%s-cur", resources[rcswhich].cap);
337	    val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_cur, limits[rcswhich].rlim_cur);
338	    limits[rcswhich].rlim_cur = resources[rcswhich].func(lc, str, val, val);
339	    /* maximum value overridden by resourcename or resourcename-max */
340	    sprintf(str, "%s-max", resources[rcswhich].cap);
341	    val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_max, limits[rcswhich].rlim_max);
342	    limits[rcswhich].rlim_max = resources[rcswhich].func(lc, str, val, val);
343	}
344    }
345
346    /* now, let's determine what we wish to do with all this */
347
348    argv += optind;
349
350    /* If we're setting limits or doing an eval (ie. we're not just
351     * displaying), then check that hard limits are not lower than
352     * soft limits, and force rasing the hard limit if we need to if
353     * we are raising the soft limit, or lower the soft limit if we
354     * are lowering the hard limit.
355     */
356    if ((*argv || doeval) && getuid() == 0) {
357
358	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
359	    if (limits[rcswhich].rlim_max != RLIM_INFINITY) {
360		if (limits[rcswhich].rlim_cur == RLIM_INFINITY) {
361		    limits[rcswhich].rlim_max = RLIM_INFINITY;
362		    which_limits[rcswhich] |= HARD;
363		} else if (limits[rcswhich].rlim_cur > limits[rcswhich].rlim_max) {
364		    if (which_limits[rcswhich] == SOFT) {
365			limits[rcswhich].rlim_max = limits[rcswhich].rlim_cur;
366			which_limits[rcswhich] |= HARD;
367		    }  else if (which_limits[rcswhich] == HARD) {
368			limits[rcswhich].rlim_cur = limits[rcswhich].rlim_max;
369			which_limits[rcswhich] |= SOFT;
370		    } else {
371			/* else.. if we're specifically setting both to
372			 * silly values, then let it error out.
373			 */
374		    }
375		}
376	    }
377	}
378    }
379
380    /* See if we've overridden anything specific on the command line */
381    if (num_limits && todo == RCSSET) {
382	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
383	    if (which_limits[rcswhich] & HARD)
384		limits[rcswhich].rlim_max = set_limits[rcswhich];
385	    if (which_limits[rcswhich] & SOFT)
386		limits[rcswhich].rlim_cur = set_limits[rcswhich];
387	}
388    }
389
390    /* If *argv is not NULL, then we are being asked to
391     * (perhaps) set environment variables and run a program
392     */
393    if (*argv) {
394	if (doeval) {
395	    warnx("-e cannot be used with `cmd' option");
396	    usage();
397	}
398
399	login_close(lc);
400
401	/* set leading environment variables, like eval(1) */
402	while (*argv && (p = strchr(*argv, '=')))
403	    (void)setenv(*argv++, ++p, 1);
404
405	/* Set limits */
406	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
407	    if (doall || num_limits == 0 || which_limits[rcswhich] != 0)
408		if (setrlimit(rcswhich, &limits[rcswhich]) == -1)
409		    err(1, "setrlimit %s", resources[rcswhich].cap);
410	}
411
412	if (*argv == NULL)
413	    usage();
414
415	execvp(*argv, argv);
416	err(1, "%s", *argv);
417    }
418
419    shelltype = doeval ? getshelltype() : SH_NONE;
420
421    if (type == ANY) /* Default to soft limits */
422	type = SOFT;
423
424    /* Display limits */
425    printf(shellparm[shelltype].cmd,
426	   lc ? " for class " : " (current)",
427	   lc ? lc->lc_class : "");
428
429    for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
430	if (doall || num_limits == 0 || which_limits[rcswhich] != 0) {
431	    if (which_limits[rcswhich] == ANY || which_limits[rcswhich])
432		which_limits[rcswhich] = type;
433	    if (shellparm[shelltype].lprm[rcswhich].pfx) {
434		if (shellparm[shelltype].both && limits[rcswhich].rlim_cur == limits[rcswhich].rlim_max) {
435		    print_limit(limits[rcswhich].rlim_max,
436				shellparm[shelltype].lprm[rcswhich].divisor,
437				shellparm[shelltype].inf,
438				shellparm[shelltype].lprm[rcswhich].pfx,
439				shellparm[shelltype].lprm[rcswhich].sfx,
440				shellparm[shelltype].both);
441		} else {
442		    if (which_limits[rcswhich] & HARD) {
443			print_limit(limits[rcswhich].rlim_max,
444				    shellparm[shelltype].lprm[rcswhich].divisor,
445				    shellparm[shelltype].inf,
446				    shellparm[shelltype].lprm[rcswhich].pfx,
447				    shellparm[shelltype].lprm[rcswhich].sfx,
448				    shellparm[shelltype].hard);
449		    }
450		    if (which_limits[rcswhich] & SOFT) {
451			print_limit(limits[rcswhich].rlim_cur,
452				    shellparm[shelltype].lprm[rcswhich].divisor,
453				    shellparm[shelltype].inf,
454				    shellparm[shelltype].lprm[rcswhich].pfx,
455				    shellparm[shelltype].lprm[rcswhich].sfx,
456				    shellparm[shelltype].soft);
457		    }
458		}
459	    }
460	}
461    }
462
463    login_close(lc);
464    exit(EXIT_SUCCESS);
465}
466
467
468static void
469usage(void)
470{
471    (void)fprintf(stderr,
472"usage: limits [-C class|-U user] [-eaSHBE] [-bcdflmnstuv [val]] [[name=val ...] cmd]\n");
473    exit(EXIT_FAILURE);
474}
475
476static void
477print_limit(rlim_t limit, unsigned divisor, const char * inf, const char * pfx, const char * sfx, const char * which)
478{
479    char numbr[64];
480
481    if (limit == RLIM_INFINITY)
482	strcpy(numbr, inf);
483    else
484	sprintf(numbr, "%jd", (intmax_t)((limit + divisor/2) / divisor));
485    printf(pfx, which, numbr);
486    printf(sfx, which);
487
488}
489
490
491static rlim_t
492resource_num(int which, int ch, const char *str)
493{
494    rlim_t res = RLIM_INFINITY;
495
496    if (str != NULL &&
497	!(strcasecmp(str, "inf") == 0 ||
498	  strcasecmp(str, "infinity") == 0 ||
499	  strcasecmp(str, "unlimit") == 0 ||
500	  strcasecmp(str, "unlimited") == 0)) {
501	const char * s = str;
502	char *e;
503
504	switch (which) {
505	case RLIMIT_CPU:	/* time values */
506	    errno = 0;
507	    res = 0;
508	    while (*s) {
509		rlim_t tim = strtoq(s, &e, 0);
510		if (e == NULL || e == s || errno)
511		    break;
512		switch (*e++) {
513		case 0:		   	/* end of string */
514		    e--;
515		default:
516		case 's': case 'S':	/* seconds */
517		    break;
518		case 'm': case 'M':	/* minutes */
519		    tim *= 60L;
520		    break;
521		case 'h': case 'H':	/* hours */
522		    tim *= (60L * 60L);
523		    break;
524		case 'd': case 'D':	/* days */
525		    tim *= (60L * 60L * 24L);
526		    break;
527		case 'w': case 'W':	/* weeks */
528		    tim *= (60L * 60L * 24L * 7L);
529		case 'y': case 'Y':	/* Years */
530		    tim *= (60L * 60L * 24L * 365L);
531		}
532		s = e;
533		res += tim;
534	    }
535	    break;
536	case RLIMIT_FSIZE: /* Size values */
537	case RLIMIT_DATA:
538	case RLIMIT_STACK:
539	case RLIMIT_CORE:
540	case RLIMIT_RSS:
541	case RLIMIT_MEMLOCK:
542	case RLIMIT_SBSIZE:
543	case RLIMIT_VMEM:
544	    errno = 0;
545	    res = 0;
546	    while (*s) {
547		rlim_t mult, tim = strtoq(s, &e, 0);
548		if (e == NULL || e == s || errno)
549		    break;
550		switch (*e++) {
551		case 0:	/* end of string */
552		    e--;
553		default:
554		    mult = 1;
555		    break;
556		case 'b': case 'B':	/* 512-byte blocks */
557		    mult = 512;
558		    break;
559		case 'k': case 'K':	/* 1024-byte Kilobytes */
560		    mult = 1024;
561		    break;
562		case 'm': case 'M':	/* 1024-k kbytes */
563		    mult = 1024 * 1024;
564		    break;
565		case 'g': case 'G':	/* 1Gbyte */
566		    mult = 1024 * 1024 * 1024;
567		    break;
568		case 't': case 'T':	/* 1TBte */
569		    mult = 1024LL * 1024LL * 1024LL * 1024LL;
570		    break;
571		}
572		s = e;
573		res += (tim * mult);
574	    }
575	    break;
576	case RLIMIT_NPROC:
577	case RLIMIT_NOFILE:
578	    res = strtoq(s, &e, 0);
579	    s = e;
580	    break;
581	}
582	if (*s) {
583	    warnx("invalid value -%c `%s'", ch, str);
584	    usage();
585	}
586    }
587    return res;
588}
589
590
591static int
592getshellbyname(const char * shell)
593{
594    int i;
595    const char * q;
596    const char * p = strrchr(shell, '/');
597
598    p = p ? p+1 : shell;
599    for (i = 0; (q = shellparm[i].name) != NULL; i++) {
600	while (*q) {
601	    int j = strcspn(q, "|");
602
603	    if (j == 0)
604		break;
605	    if (strncmp(p, q, j) == 0)
606		return i;
607	    if (*(q += j))
608		++q;
609	}
610    }
611    return SH_SH;
612}
613
614
615/*
616 * Determine the type of shell our parent process is
617 * This is quite tricky, not 100% reliable and probably
618 * not nearly as thorough as it should be. Basically, this
619 * is a "best guess" only, but hopefully will work in
620 * most cases.
621 */
622
623static int
624getshelltype(void)
625{
626    pid_t ppid = getppid();
627
628    if (ppid != 1) {
629	FILE * fp;
630	struct stat st;
631	char procdir[MAXPATHLEN], buf[128];
632	int l = sprintf(procdir, "/proc/%ld/", (long)ppid);
633	char * shell = getenv("SHELL");
634
635	if (shell != NULL && stat(shell, &st) != -1) {
636	    struct stat st1;
637
638	    strcpy(procdir+l, "file");
639	    /* $SHELL is actual shell? */
640	    if (stat(procdir, &st1) != -1 && memcmp(&st, &st1, sizeof st) == 0)
641		return getshellbyname(shell);
642	}
643	strcpy(procdir+l, "status");
644	if (stat(procdir, &st) == 0 && (fp = fopen(procdir, "r")) != NULL) {
645	    char * p = fgets(buf, sizeof buf, fp)==NULL ? NULL : strtok(buf, " \t");
646	    fclose(fp);
647	    if (p != NULL)
648		return getshellbyname(p);
649	}
650    }
651    return SH_SH;
652}
653
654