xref: /freebsd/usr.bin/limits/limits.c (revision ce834215a70ff69e7e222827437116eee2f9ac6f)
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  *	$Id: limits.c,v 1.3 1997/03/29 04:30:26 imp Exp $
24  */
25 
26 #include <err.h>
27 #include <stdio.h>
28 #include <string.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/param.h>
32 #include <stdlib.h>
33 #include <unistd.h>
34 #include <stdarg.h>
35 #include <ctype.h>
36 #include <errno.h>
37 #include <pwd.h>
38 #include <login_cap.h>
39 #include <sys/time.h>
40 #include <sys/resource.h>
41 
42 enum
43 {
44     SH_NONE,
45     SH_SH,      /* sh */
46     SH_CSH,     /* csh */
47     SH_BASH,    /* gnu bash */
48     SH_TCSH,    /* tcsh */
49     SH_KSH,     /* (pd)ksh */
50     SH_ZSH,     /* zsh */
51     SH_RC,      /* rc or es */
52     SH_NUMBER
53 };
54 
55 
56 /* eval emitter for popular shells.
57  * Why aren't there any standards here? Most shells support either
58  * the csh 'limit' or sh 'ulimit' command, but each varies just
59  * enough that they aren't very compatible from one to the other.
60  */
61 static struct {
62     const char * name;	    /* Name of shell */
63     const char * inf;	    /* Name used for 'unlimited' resource */
64     const char * cmd;	    /* Intro text */
65     const char * hard;	    /* Hard limit text */
66     const char * soft;	    /* Soft limit text */
67     const char * both;	    /* Hard+Soft limit text */
68     struct {
69 	const char * pfx;
70 	const char * sfx;
71 	int divisor;
72     } lprm[RLIM_NLIMITS];
73 } shellparm[] =
74 {
75     { "", "infinity", "Resource limits%s%s:\n", "-max", "-cur", "",
76       {
77 	  { "  cputime%-4s      %8s", " secs\n",  1    },
78 	  { "  filesize%-4s     %8s", " kb\n",    1024 },
79 	  { "  datasize%-4s     %8s", " kb\n",    1024 },
80 	  { "  stacksize%-4s    %8s", " kb\n",    1024 },
81 	  { "  coredumpsize%-4s %8s", " kb\n",    1024 },
82 	  { "  memoryuse%-4s    %8s", " kb\n",    1024 },
83 	  { "  memorylocked%-4s %8s", " kb\n",    1024 },
84 	  { "  maxprocesses%-4s %8s", "\n",       1    },
85 	  { "  openfiles%-4s    %8s", "\n",       1    }
86       }
87     },
88     { "sh", "unlimited", "", " -H", " -S", "",
89       {
90 	  { "ulimit%s -t %s", ";\n",  1    },
91 	  { "ulimit%s -f %s", ";\n",  512  },
92 	  { "ulimit%s -d %s", ";\n",  1024 },
93 	  { "ulimit%s -s %s", ";\n",  1024 },
94 	  { "ulimit%s -c %s", ";\n",  512  },
95 	  { "ulimit%s -m %s", ";\n",  1024 },
96 	  { "ulimit%s -l %s", ";\n",  1024 },
97 	  { "ulimit%s -u %s", ";\n",  1    },
98 	  { "ulimit%s -n %s", ";\n",  1    }
99       }
100     },
101     { "csh", "unlimited", "", " -h", "", NULL,
102       {
103 	  { "limit%s cputime %s",      ";\n",  1    },
104 	  { "limit%s filesize %s",     ";\n",  1024 },
105 	  { "limit%s datasize %s",     ";\n",  1024 },
106 	  { "limit%s stacksize %s",    ";\n",  1024 },
107 	  { "limit%s coredumpsize %s", ";\n",  1024 },
108 	  { "limit%s memoryuse %s",    ";\n",  1024 },
109 	  { "limit%s memorylocked %s", ";\n",  1024 },
110 	  { "limit%s maxproc %s",      ";\n",  1    },
111 	  { "limit%s openfiles %s",    ";\n",  1    }
112       }
113     },
114     { "bash|bash2", "unlimited", "", " -H", " -S", "",
115       {
116 	  { "ulimit%s -t %s", ";\n",  1    },
117 	  { "ulimit%s -f %s", ";\n",  1024 },
118 	  { "ulimit%s -d %s", ";\n",  1024 },
119 	  { "ulimit%s -s %s", ";\n",  1024 },
120 	  { "ulimit%s -c %s", ";\n",  1024 },
121 	  { "ulimit%s -m %s", ";\n",  1024 },
122 	  { "ulimit%s -l %s", ";\n",  1024 },
123 	  { "ulimit%s -u %s", ";\n",  1    },
124 	  { "ulimit%s -n %s", ";\n",  1    }
125       }
126     },
127     { "tcsh", "unlimited", "", " -h", "", NULL,
128       {
129 	  { "limit%s cputime %s",      ";\n",  1    },
130 	  { "limit%s filesize %s",     ";\n",  1024 },
131 	  { "limit%s datasize %s",     ";\n",  1024 },
132 	  { "limit%s stacksize %s",    ";\n",  1024 },
133 	  { "limit%s coredumpsize %s", ";\n",  1024 },
134 	  { "limit%s memoryuse %s",    ";\n",  1024 },
135 	  { "limit%s memorylocked %s", ";\n",  1024 },
136 	  { "limit%s maxproc %s",      ";\n",  1    },
137 	  { "limit%s descriptors %s",  ";\n",  1    }
138       }
139     },
140     { "ksh|pdksh", "unlimited", "", " -H", " -S", "",
141       {
142 	  { "ulimit%s -t %s", ";\n",  1    },
143 	  { "ulimit%s -f %s", ";\n",  512  },
144 	  { "ulimit%s -d %s", ";\n",  1024 },
145 	  { "ulimit%s -s %s", ";\n",  1024 },
146 	  { "ulimit%s -c %s", ";\n",  512  },
147 	  { "ulimit%s -m %s", ";\n",  1024 },
148 	  { "ulimit%s -l %s", ";\n",  1024 },
149 	  { "ulimit%s -p %s", ";\n",  1    },
150 	  { "ulimit%s -n %s", ";\n",  1    }
151       }
152     },
153     { "zsh", "unlimited", "", " -H", " -S", "",
154       {
155 	  { "ulimit%s -t %s", ";\n",  1    },
156 	  { "ulimit%s -f %s", ";\n",  512  },
157 	  { "ulimit%s -d %s", ";\n",  1024 },
158 	  { "ulimit%s -s %s", ";\n",  1024 },
159 	  { "ulimit%s -c %s", ";\n",  512  },
160 	  { "ulimit%s -m %s", ";\n",  1024 },
161 	  { "ulimit%s -l %s", ";\n",  1024 },
162 	  { "ulimit%s -u %s", ";\n",  1    },
163 	  { "ulimit%s -n %s", ";\n",  1    }
164       }
165     },
166     { "rc|es", "unlimited", "", " -h", "", NULL,
167       {
168 	  { "limit%s cputime %s",      ";\n",  1    },
169 	  { "limit%s filesize %s",     ";\n",  1024 },
170 	  { "limit%s datasize %s",     ";\n",  1024 },
171 	  { "limit%s stacksize %s",    ";\n",  1024 },
172 	  { "limit%s coredumpsize %s", ";\n",  1024 },
173 	  { "limit%s memoryuse %s",    ";\n",  1024 },
174 	  { "limit%s lockedmemory %s", ";\n",  1024 },
175 	  { "limit%s processes %s",    ";\n",  1    },
176 	  { "limit%s descriptors %s",  ";\n",  1    }
177       }
178     },
179     { NULL }
180 };
181 
182 static struct {
183     const char * cap;
184     rlim_t (*func)(login_cap_t *, const char *, rlim_t, rlim_t);
185 } resources[RLIM_NLIMITS] = {
186     { "cputime",	login_getcaptime },
187     { "filesize",	login_getcapsize },
188     { "datasize",	login_getcapsize },
189     { "stacksize",	login_getcapsize },
190     { "coredumpsize",	login_getcapsize },
191     { "memoryuse",	login_getcapsize },
192     { "memorylocked",	login_getcapsize },
193     { "maxproc",	login_getcapnum, },
194     { "openfiles",	login_getcapnum  }
195 };
196 
197 /*
198  * One letter for each resource levels.
199  * NOTE: There is a dependancy on the corresponding
200  * letter index being equal to the resource number.
201  * If sys/resource.h defines are changed, this needs
202  * to be modified accordingly!
203  */
204 
205 #define RCS_STRING  "tfdscmlun"
206 
207 static rlim_t resource_num(int which, int ch, const char *str);
208 static void usage(const char *msg, ...);
209 static int getshelltype(void);
210 static void print_limit(rlim_t limit, unsigned divisor, const char *inf,
211 			const char *pfx, const char *sfx, const char *which);
212 extern char **environ;
213 
214 static const char rcs_string[] = RCS_STRING;
215 
216 int
217 main(int argc, char *argv[])
218 {
219     char *p, *cls = NULL;
220     char *cleanenv[1];
221     struct passwd * pwd = NULL;
222     int rcswhich, shelltype;
223     int i, num_limits = 0;
224     int ch, doeval = 0, doall = 0;
225     login_cap_t * lc = NULL;
226     enum { ANY=0, SOFT=1, HARD=2, BOTH=3, DISPLAYONLY=4 } type = ANY;
227     enum { RCSUNKNOWN=0, RCSSET=1, RCSSEL=2 } todo = RCSUNKNOWN;
228     int which_limits[RLIM_NLIMITS];
229     rlim_t set_limits[RLIM_NLIMITS];
230     struct rlimit limits[RLIM_NLIMITS];
231 
232     /* init resource tables */
233     for (i = 0; i < RLIM_NLIMITS; i++) {
234 	which_limits[i] = 0; /* Don't set/display any */
235 	set_limits[i] = RLIM_INFINITY;
236 	/* Get current resource values */
237 	getrlimit(i, &limits[i]);
238     }
239 
240     optarg = NULL;
241     while ((ch = getopt(argc, argv, ":EeC:U:BSHac:d:f:l:m:n:s:t:u:")) != -1) {
242 	switch(ch) {
243 	case 'a':
244 	    doall = 1;
245 	    break;
246 	case 'E':
247 	    environ = cleanenv;
248 	    cleanenv[0] = NULL;
249 	    break;
250 	case 'e':
251 	    doeval = 1;
252 	    break;
253 	case 'C':
254 	    cls = optarg;
255 	    break;
256 	case 'U':
257 	    if ((pwd = getpwnam(optarg)) == NULL) {
258 		if (!isdigit(*optarg) ||
259 		    (pwd = getpwuid(atoi(optarg))) == NULL) {
260 		    usage("Invalid user `%s'\n", optarg);
261 		}
262 	    }
263 	    break;
264 	case 'H':
265 	    type = HARD;
266 	    break;
267 	case 'S':
268 	    type = SOFT;
269 	    break;
270 	case 'B':
271 	    type = SOFT|HARD;
272 	    break;
273 	default:
274 	case ':': /* Without arg */
275 	    if ((p = strchr(rcs_string, optopt)) != NULL) {
276 		int rcswhich = p - rcs_string;
277 		if (optarg && *optarg == '-') { /* 'arg' is actually a switch */
278 		    --optind;		/* back one arg, and make arg NULL */
279 		    optarg = NULL;
280 		}
281 		todo = optarg == NULL ? RCSSEL : RCSSET;
282 		if (type == ANY)
283 		    type = BOTH;
284 		which_limits[rcswhich] = optarg ? type : DISPLAYONLY;
285 		set_limits[rcswhich] = resource_num(rcswhich, optopt, optarg);
286 		num_limits++;
287 		break;
288 	    }
289 	    /* FALLTHRU */
290 	case '?':
291 	    usage(NULL);
292 	}
293 	optarg = NULL;
294     }
295 
296     /* If user was specified, get class from that */
297     if (pwd != NULL)
298 	lc = login_getpwclass(pwd);
299     else if (cls != NULL && *cls != '\0') {
300 	lc = login_getclassbyname(cls, NULL);
301 	if (lc == NULL || strcmp(cls, lc->lc_class) != 0)
302 	    fprintf(stderr, "login class '%s' non-existent, using %s\n",
303 		    cls, lc?lc->lc_class:"current settings");
304     }
305 
306     /* If we have a login class, update resource table from that */
307     if (lc != NULL) {
308 	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
309 	    char str[40];
310 	    rlim_t val;
311 
312 	    /* current value overridden by resourcename or resourcename-cur */
313 	    sprintf(str, "%s-cur", resources[rcswhich].cap);
314 	    val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_cur, limits[rcswhich].rlim_cur);
315 	    limits[rcswhich].rlim_cur = resources[rcswhich].func(lc, str, val, val);
316 	    /* maximum value overridden by resourcename or resourcename-max */
317 	    sprintf(str, "%s-max", resources[rcswhich].cap);
318 	    val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_max, limits[rcswhich].rlim_max);
319 	    limits[rcswhich].rlim_max = resources[rcswhich].func(lc, str, val, val);
320 	}
321     }
322 
323     /* now, let's determine what we wish to do with all this */
324 
325     argv += optind;
326 
327     /* If we're setting limits or doing an eval (ie. we're not just
328      * displaying), then check that hard limits are not lower than
329      * soft limits, and force rasing the hard limit if we need to if
330      * we are raising the soft limit, or lower the soft limit if we
331      * are lowering the hard limit.
332      */
333     if ((*argv || doeval) && getuid() == 0) {
334 
335 	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
336 	    if (limits[rcswhich].rlim_max != RLIM_INFINITY) {
337 		if (limits[rcswhich].rlim_cur == RLIM_INFINITY) {
338 		    limits[rcswhich].rlim_max = RLIM_INFINITY;
339 		    which_limits[rcswhich] |= HARD;
340 		} else if (limits[rcswhich].rlim_cur > limits[rcswhich].rlim_max) {
341 		    if (which_limits[rcswhich] == SOFT) {
342 			limits[rcswhich].rlim_max = limits[rcswhich].rlim_cur;
343 			which_limits[rcswhich] |= HARD;
344 		    }  else if (which_limits[rcswhich] == HARD) {
345 			limits[rcswhich].rlim_cur = limits[rcswhich].rlim_max;
346 			which_limits[rcswhich] |= SOFT;
347 		    } else {
348 			/* else.. if we're specifically setting both to
349 			 * silly values, then let it error out.
350 			 */
351 		    }
352 		}
353 	    }
354 	}
355     }
356 
357     /* See if we've overridden anything specific on the command line */
358     if (num_limits && todo == RCSSET) {
359 	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
360 	    if (which_limits[rcswhich] & HARD)
361 		limits[rcswhich].rlim_max = set_limits[rcswhich];
362 	    if (which_limits[rcswhich] & SOFT)
363 		limits[rcswhich].rlim_cur = set_limits[rcswhich];
364 	}
365     }
366 
367     /* If *argv is not NULL, then we are being asked to
368      * (perhaps) set environment variables and run a program
369      */
370     if (*argv) {
371 	if (doeval)
372 	    usage("-e cannot be used with `cmd' option\n");
373 
374 	login_close(lc);
375 
376 	/* set leading environment variables, like eval(1) */
377 	while (*argv && (p = strchr(*argv, '=')))
378 	    (void)setenv(*argv++, ++p, 1);
379 
380 	/* Set limits */
381 	for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
382 	    if (doall || num_limits == 0 || which_limits[rcswhich] != 0)
383 		if (setrlimit(rcswhich, &limits[rcswhich]) == -1)
384 		    err(1, "setrlimit %s", resources[rcswhich].cap);
385 	}
386 
387 	if (*argv == NULL)
388 	    usage(NULL);
389 
390 	execvp(*argv, argv);
391 	err(1, "%s", *argv);
392     }
393 
394     shelltype = doeval ? getshelltype() : SH_NONE;
395 
396     if (type == ANY) /* Default to soft limits */
397 	type = SOFT;
398 
399     /* Display limits */
400     printf(shellparm[shelltype].cmd,
401 	   lc ? " for class " : " (current)",
402 	   lc ? lc->lc_class : "");
403 
404     for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
405 	if (doall || num_limits == 0 || which_limits[rcswhich] != 0) {
406 	    if (which_limits[rcswhich] == ANY || which_limits[rcswhich])
407 		which_limits[rcswhich] = type;
408 	    if (shellparm[shelltype].lprm[rcswhich].pfx) {
409 		if (shellparm[shelltype].both && limits[rcswhich].rlim_cur == limits[rcswhich].rlim_max) {
410 		    print_limit(limits[rcswhich].rlim_max,
411 				shellparm[shelltype].lprm[rcswhich].divisor,
412 				shellparm[shelltype].inf,
413 				shellparm[shelltype].lprm[rcswhich].pfx,
414 				shellparm[shelltype].lprm[rcswhich].sfx,
415 				shellparm[shelltype].both);
416 		} else {
417 		    if (which_limits[rcswhich] & HARD) {
418 			print_limit(limits[rcswhich].rlim_max,
419 				    shellparm[shelltype].lprm[rcswhich].divisor,
420 				    shellparm[shelltype].inf,
421 				    shellparm[shelltype].lprm[rcswhich].pfx,
422 				    shellparm[shelltype].lprm[rcswhich].sfx,
423 				    shellparm[shelltype].hard);
424 		    }
425 		    if (which_limits[rcswhich] & SOFT) {
426 			print_limit(limits[rcswhich].rlim_cur,
427 				    shellparm[shelltype].lprm[rcswhich].divisor,
428 				    shellparm[shelltype].inf,
429 				    shellparm[shelltype].lprm[rcswhich].pfx,
430 				    shellparm[shelltype].lprm[rcswhich].sfx,
431 				    shellparm[shelltype].soft);
432 		    }
433 		}
434 	    }
435 	}
436     }
437 
438     login_close(lc);
439     exit(EXIT_SUCCESS);
440 }
441 
442 
443 static void
444 usage(char const *msg, ...)
445 {
446     if (msg) {
447 	va_list argp;
448 	va_start(argp, msg);
449 	vfprintf(stderr, msg, argp);
450 	va_end(argp);
451     }
452     (void)fprintf(stderr,
453     "limits [-C class|-U user] [-eaSHBE] [-cdflmnstu [val]] [[name=val ...] cmd]\n");
454     exit(EXIT_FAILURE);
455 }
456 
457 static void
458 print_limit(rlim_t limit, unsigned divisor, const char * inf, const char * pfx, const char * sfx, const char * which)
459 {
460     char numbr[64];
461 
462     if (limit == RLIM_INFINITY)
463 	strcpy(numbr, inf);
464     else
465 	sprintf(numbr, "%qd", (quad_t)((limit + divisor/2) / divisor));
466     printf(pfx, which, numbr);
467     printf(sfx, which);
468 
469 }
470 
471 
472 static rlim_t
473 resource_num(int which, int ch, const char *str)
474 {
475     rlim_t res = RLIM_INFINITY;
476 
477     if (str != NULL &&
478 	!(strcasecmp(str, "inf") == 0 ||
479 	  strcasecmp(str, "infinity") == 0 ||
480 	  strcasecmp(str, "unlimit") == 0 ||
481 	  strcasecmp(str, "unlimited") == 0)) {
482 	const char * s = str;
483 	char *e;
484 
485 	switch (which) {
486 	case RLIMIT_CPU:	/* time values */
487 	    errno = 0;
488 	    res = 0;
489 	    while (*s) {
490 		rlim_t tim = strtoq(s, &e, 0);
491 		if (e == NULL || e == s || errno)
492 		    break;
493 		switch (*e++) {
494 		case 0:		   	/* end of string */
495 		    e--;
496 		default:
497 		case 's': case 'S':	/* seconds */
498 		    break;
499 		case 'm': case 'M':	/* minutes */
500 		    tim *= 60L;
501 		    break;
502 		case 'h': case 'H':	/* hours */
503 		    tim *= (60L * 60L);
504 		    break;
505 		case 'd': case 'D':	/* days */
506 		    tim *= (60L * 60L * 24L);
507 		    break;
508 		case 'w': case 'W':	/* weeks */
509 		    tim *= (60L * 60L * 24L * 7L);
510 		case 'y': case 'Y':	/* Years */
511 		    tim *= (60L * 60L * 24L * 365L);
512 		}
513 		s = e;
514 		res += tim;
515 	    }
516 	    break;
517 	case RLIMIT_FSIZE: /* Size values */
518 	case RLIMIT_DATA:
519 	case RLIMIT_STACK:
520 	case RLIMIT_CORE:
521 	case RLIMIT_RSS:
522 	case RLIMIT_MEMLOCK:
523 	    errno = 0;
524 	    res = 0;
525 	    while (*s) {
526 		rlim_t mult, tim = strtoq(s, &e, 0);
527 		if (e == NULL || e == s || errno)
528 		    break;
529 		switch (*e++) {
530 		case 0:	/* end of string */
531 		    e--;
532 		default:
533 		    mult = 1;
534 		    break;
535 		case 'b': case 'B':	/* 512-byte blocks */
536 		    mult = 512;
537 		    break;
538 		case 'k': case 'K':	/* 1024-byte Kilobytes */
539 		    mult = 1024;
540 		    break;
541 		case 'm': case 'M':	/* 1024-k kbytes */
542 		    mult = 1024 * 1024;
543 		    break;
544 		case 'g': case 'G':	/* 1Gbyte */
545 		    mult = 1024 * 1024 * 1024;
546 		    break;
547 		case 't': case 'T':	/* 1TBte */
548 		    mult = 1024LL * 1024LL * 1024LL * 1024LL;
549 		    break;
550 		}
551 		s = e;
552 		res += (tim * mult);
553 	    }
554 	    break;
555 	case RLIMIT_NPROC:
556 	case RLIMIT_NOFILE:
557 	    res = strtoq(s, &e, 0);
558 	    s = e;
559 	    break;
560 	}
561 	if (*s)
562 	    usage("invalid value -%c `%s'\n", ch, str);
563     }
564     return res;
565 }
566 
567 
568 static int
569 getshellbyname(const char * shell)
570 {
571     int i;
572     const char * q;
573     const char * p = strrchr(shell, '/');
574 
575     p = p ? ++p : shell;
576     for (i = 0; (q = shellparm[i].name) != NULL; i++) {
577 	while (*q) {
578 	    int j = strcspn(q, "|");
579 
580 	    if (j == 0)
581 		break;
582 	    if (strncmp(p, q, j) == 0)
583 		return i;
584 	    if (*(q += j))
585 		++q;
586 	}
587     }
588     return SH_SH;
589 }
590 
591 
592 /*
593  * Determine the type of shell our parent process is
594  * This is quite tricky, not 100% reliable and probably
595  * not nearly as thorough as it should be. Basically, this
596  * is a "best guess" only, but hopefully will work in
597  * most cases.
598  */
599 
600 static int
601 getshelltype(void)
602 {
603     pid_t ppid = getppid();
604 
605     if (ppid != 1) {
606 	FILE * fp;
607 	struct stat st;
608 	char procdir[MAXPATHLEN], buf[128];
609 	int l = sprintf(procdir, "/proc/%ld/", (long)ppid);
610 	char * shell = getenv("SHELL");
611 
612 	if (shell != NULL && stat(shell, &st) != -1) {
613 	    struct stat st1;
614 
615 	    strcpy(procdir+l, "file");
616 	    /* $SHELL is actual shell? */
617 	    if (stat(procdir, &st1) != -1 && memcmp(&st, &st1, sizeof st) == 0)
618 		return getshellbyname(shell);
619 	}
620 	strcpy(procdir+l, "status");
621 	if (stat(procdir, &st) == 0 && (fp = fopen(procdir, "r")) != NULL) {
622 	    char * p = fgets(buf, sizeof buf, fp)==NULL ? NULL : strtok(buf, " \t");
623 	    fclose(fp);
624 	    if (p != NULL)
625 		return getshellbyname(p);
626 	}
627     }
628     return SH_SH;
629 }
630 
631