/*-
 * Copyright (c) 1997 by
 * David L. Nugent <davidn@blaze.net.au>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, is permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. This work was done expressly for inclusion into FreeBSD.  Other use
 *    is permitted provided this notation is included.
 * 4. Absolutely no warranty of function or purpose is made by the authors.
 * 5. Modifications may be freely made to this file providing the above
 *    conditions are met.
 *
 * Display/change(+runprogram)/eval resource limits.
 */

#include <sys/cdefs.h>
#include <err.h>
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <sys/param.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdint.h>
#include <ctype.h>
#include <errno.h>
#include <pwd.h>
#include <login_cap.h>
#include <sys/time.h>
#include <sys/resource.h>

enum
{
    SH_NONE,
    SH_SH,      /* sh */
    SH_CSH,     /* csh */
    SH_BASH,    /* gnu bash */
    SH_TCSH,    /* tcsh */
    SH_KSH,     /* (pd)ksh */
    SH_ZSH,     /* zsh */
    SH_RC,      /* rc or es */
    SH_NUMBER
};


/* eval emitter for popular shells.
 * Why aren't there any standards here? Most shells support either
 * the csh 'limit' or sh 'ulimit' command, but each varies just
 * enough that they aren't very compatible from one to the other.
 */
static struct {
    const char * name;      /* Name of shell */
    const char * inf;       /* Name used for 'unlimited' resource */
    const char * cmd;       /* Intro text */
    const char * hard;      /* Hard limit text */
    const char * soft;      /* Soft limit text */
    const char * both;      /* Hard+Soft limit text */
    struct {
        const char * pfx;
        const char * sfx;
        int divisor;
    } lprm[RLIM_NLIMITS];
} shellparm[] =
{
    { "", "infinity", "Resource limits%s%s:\n", "-max", "-cur", "",
      {
          { "  cputime%-4s          %8s", " secs\n",  1    },
          { "  filesize%-4s         %8s", " kB\n",    1024 },
          { "  datasize%-4s         %8s", " kB\n",    1024 },
          { "  stacksize%-4s        %8s", " kB\n",    1024 },
          { "  coredumpsize%-4s     %8s", " kB\n",    1024 },
          { "  memoryuse%-4s        %8s", " kB\n",    1024 },
          { "  memorylocked%-4s     %8s", " kB\n",    1024 },
          { "  maxprocesses%-4s     %8s", "\n",       1    },
          { "  openfiles%-4s        %8s", "\n",       1    },
          { "  sbsize%-4s           %8s", " bytes\n", 1    },
          { "  vmemoryuse%-4s       %8s", " kB\n",    1024 },
          { "  pseudo-terminals%-4s %8s", "\n",       1    },
          { "  swapuse%-4s          %8s", " kB\n",    1024 },
          { "  kqueues%-4s          %8s", "\n",       1    },
          { "  umtxp%-4s            %8s", "\n",       1    },
          { "  pipebuf%-4s          %8s", " kB\n",    1024 },
      }
    },
    { "sh", "unlimited", "", " -H", " -S", "",
      {
          { "ulimit%s -t %s", ";\n",  1    },
          { "ulimit%s -f %s", ";\n",  512  },
          { "ulimit%s -d %s", ";\n",  1024 },
          { "ulimit%s -s %s", ";\n",  1024 },
          { "ulimit%s -c %s", ";\n",  512  },
          { "ulimit%s -m %s", ";\n",  1024 },
          { "ulimit%s -l %s", ";\n",  1024 },
          { "ulimit%s -u %s", ";\n",  1    },
          { "ulimit%s -n %s", ";\n",  1    },
          { "ulimit%s -b %s", ";\n",  1    },
          { "ulimit%s -v %s", ";\n",  1024 },
          { "ulimit%s -p %s", ";\n",  1    },
          { "ulimit%s -w %s", ";\n",  1024 },
          { "ulimit%s -k %s", ";\n",  1    },
          { "ulimit%s -o %s", ";\n",  1    },
          { "ulimit%s -y %s", ";\n",  1024 },
      }
    },
    { "csh", "unlimited", "", " -h", "", NULL,
      {
          { "limit%s cputime %s",         ";\n",  1    },
          { "limit%s filesize %s",        ";\n",  1024 },
          { "limit%s datasize %s",        ";\n",  1024 },
          { "limit%s stacksize %s",       ";\n",  1024 },
          { "limit%s coredumpsize %s",    ";\n",  1024 },
          { "limit%s memoryuse %s",       ";\n",  1024 },
          { "limit%s memorylocked %s",    ";\n",  1024 },
          { "limit%s maxproc %s",         ";\n",  1    },
          { "limit%s openfiles %s",       ";\n",  1    },
          { "limit%s sbsize %s",          ";\n",  1    },
          { "limit%s vmemoryuse %s",      ";\n",  1024 },
          { "limit%s pseudoterminals %s", ";\n",  1    },
          { "limit%s swapsize %s",        ";\n",  1024 },
          { "limit%s kqueues %s",         ";\n",  1    },
          { "limit%s umtxp %s",           ";\n",  1    },
      }
    },
    { "bash|bash2", "unlimited", "", " -H", " -S", "",
      {
          { "ulimit%s -t %s", ";\n",  1    },
          { "ulimit%s -f %s", ";\n",  1024 },
          { "ulimit%s -d %s", ";\n",  1024 },
          { "ulimit%s -s %s", ";\n",  1024 },
          { "ulimit%s -c %s", ";\n",  1024 },
          { "ulimit%s -m %s", ";\n",  1024 },
          { "ulimit%s -l %s", ";\n",  1024 },
          { "ulimit%s -u %s", ";\n",  1    },
          { "ulimit%s -n %s", ";\n",  1    },
          { "ulimit%s -b %s", ";\n",  1    },
          { "ulimit%s -v %s", ";\n",  1024 },
          { "ulimit%s -p %s", ";\n",  1    },
          { "ulimit%s -w %s", ";\n",  1024 }
      }
    },
    { "tcsh", "unlimited", "", " -h", "", NULL,
      {
          { "limit%s cputime %s",         ";\n",  1    },
          { "limit%s filesize %s",        ";\n",  1024 },
          { "limit%s datasize %s",        ";\n",  1024 },
          { "limit%s stacksize %s",       ";\n",  1024 },
          { "limit%s coredumpsize %s",    ";\n",  1024 },
          { "limit%s memoryuse %s",       ";\n",  1024 },
          { "limit%s memorylocked %s",    ";\n",  1024 },
          { "limit%s maxproc %s",         ";\n",  1    },
          { "limit%s descriptors %s",     ";\n",  1    },
          { "limit%s sbsize %s",          ";\n",  1    },
          { "limit%s vmemoryuse %s",      ";\n",  1024 },
          { "limit%s pseudoterminals %s", ";\n",  1    },
          { "limit%s swapsize %s",        ";\n",  1024 },
          { "limit%s kqueues %s",         ";\n",  1    },
          { "limit%s umtxp %s",           ";\n",  1    },
      }
    },
    { "ksh|pdksh", "unlimited", "", " -H", " -S", "",
      {
          { "ulimit%s -t %s", ";\n",  1    },
          { "ulimit%s -f %s", ";\n",  512  },
          { "ulimit%s -d %s", ";\n",  1024 },
          { "ulimit%s -s %s", ";\n",  1024 },
          { "ulimit%s -c %s", ";\n",  512  },
          { "ulimit%s -m %s", ";\n",  1024 },
          { "ulimit%s -l %s", ";\n",  1024 },
          { "ulimit%s -p %s", ";\n",  1    },
          { "ulimit%s -n %s", ";\n",  1    },
          { "ulimit%s -b %s", ";\n",  1    },
          { "ulimit%s -v %s", ";\n",  1024 },
          { "ulimit%s -p %s", ";\n",  1    },
          { "ulimit%s -w %s", ";\n",  1024 }
      }
    },
    { "zsh", "unlimited", "", " -H", " -S", "",
      {
          { "ulimit%s -t %s", ";\n",  1    },
          { "ulimit%s -f %s", ";\n",  512  },
          { "ulimit%s -d %s", ";\n",  1024 },
          { "ulimit%s -s %s", ";\n",  1024 },
          { "ulimit%s -c %s", ";\n",  512  },
          { "ulimit%s -m %s", ";\n",  1024 },
          { "ulimit%s -l %s", ";\n",  1024 },
          { "ulimit%s -u %s", ";\n",  1    },
          { "ulimit%s -n %s", ";\n",  1    },
          { "ulimit%s -b %s", ";\n",  1    },
          { "ulimit%s -v %s", ";\n",  1024 },
          { "ulimit%s -p %s", ";\n",  1    },
          { "ulimit%s -w %s", ";\n",  1024 }
      }
    },
    { "rc|es", "unlimited", "", " -h", "", NULL,
      {
          { "limit%s cputime %s",         ";\n",  1    },
          { "limit%s filesize %s",        ";\n",  1024 },
          { "limit%s datasize %s",        ";\n",  1024 },
          { "limit%s stacksize %s",       ";\n",  1024 },
          { "limit%s coredumpsize %s",    ";\n",  1024 },
          { "limit%s memoryuse %s",       ";\n",  1024 },
          { "limit%s lockedmemory %s",    ";\n",  1024 },
          { "limit%s processes %s",       ";\n",  1    },
          { "limit%s descriptors %s",     ";\n",  1    },
          { "limit%s sbsize %s",          ";\n",  1    },
          { "limit%s vmemoryuse %s",      ";\n",  1024 },
          { "limit%s pseudoterminals %s", ";\n",  1    },
          { "limit%s swapuse %s",         ";\n",  1024 }
      }
    },
    { NULL, NULL, NULL, NULL, NULL, NULL,
      { }
    }
};

static struct {
    const char * cap;
    rlim_t (*func)(login_cap_t *, const char *, rlim_t, rlim_t);
} resources[] = {
    { "cputime",        login_getcaptime },
    { "filesize",       login_getcapsize },
    { "datasize",       login_getcapsize },
    { "stacksize",      login_getcapsize },
    { "coredumpsize",   login_getcapsize },
    { "memoryuse",      login_getcapsize },
    { "memorylocked",   login_getcapsize },
    { "maxproc",        login_getcapnum  },
    { "openfiles",      login_getcapnum  },
    { "sbsize",         login_getcapsize },
    { "vmemoryuse",     login_getcapsize },
    { "pseudoterminals",login_getcapnum  },
    { "swapuse",        login_getcapsize },
    { "kqueues",        login_getcapnum  },
    { "umtxp",          login_getcapnum  },
    { "pipebuf",        login_getcapnum  },
    { "vmms",           login_getcapnum  },
};

_Static_assert(nitems(resources) == RLIM_NLIMITS,
    "Please add entries to resources[] for the new limits");

/*
 * One letter for each resource levels.
 * NOTE: There is a dependency on the corresponding
 * letter index being equal to the resource number.
 * If sys/resource.h defines are changed, this needs
 * to be modified accordingly!
 */
static const char rcs_string[] = "tfdscmlunbvpwkoyV";
_Static_assert(sizeof(rcs_string) - 1 == RLIM_NLIMITS,
    "Please add letters to rcs_string[] for the new limits");

static rlim_t resource_num(int which, int ch, const char *str);
static void usage(void) __dead2;
static int getshelltype(void);
static void print_limit(rlim_t limit, unsigned divisor, const char *inf,
                        const char *pfx, const char *sfx, const char *which);
static void getrlimit_proc(pid_t pid, int resource, struct rlimit *rlp);
static void setrlimit_proc(pid_t pid, int resource, const struct rlimit *rlp);
extern char **environ;

int
main(int argc, char *argv[])
{
    char *p, *cls = NULL;
    char *cleanenv[1];
    struct passwd * pwd = NULL;
    int rcswhich, shelltype;
    int i, num_limits = 0;
    int ch, doeval = 0, doall = 0;
    int rtrn, setproc;
    login_cap_t * lc = NULL;
    enum { ANY=0, SOFT=1, HARD=2, BOTH=3, DISPLAYONLY=4 } type = ANY;
    enum { RCSUNKNOWN=0, RCSSET=1, RCSSEL=2 } todo = RCSUNKNOWN;
    int which_limits[RLIM_NLIMITS];
    rlim_t set_limits[RLIM_NLIMITS];
    struct rlimit limits[RLIM_NLIMITS];
    pid_t pid;

    /* init resource tables */
    for (i = 0; i < RLIM_NLIMITS; i++) {
        which_limits[i] = 0; /* Don't set/display any */
        set_limits[i] = RLIM_INFINITY;
    }

    pid = -1;
    optarg = NULL;
    while ((ch = getopt(argc, argv,
      ":ab:BC:c:d:Eef:Hk:l:m:n:o:P:p:Ss:t:U:u:V:v:w:y:")) != -1) {
        switch(ch) {
        case 'a':
            doall = 1;
            break;
        case 'E':
            environ = cleanenv;
            cleanenv[0] = NULL;
            break;
        case 'e':
            doeval = 1;
            break;
        case 'C':
            cls = optarg;
            break;
        case 'U':
            if ((pwd = getpwnam(optarg)) == NULL) {
                if (!isdigit(*optarg) ||
                    (pwd = getpwuid(atoi(optarg))) == NULL) {
                    warnx("invalid user `%s'", optarg);
                    usage();
                }
            }
            break;
        case 'H':
            type = HARD;
            break;
        case 'S':
            type = SOFT;
            break;
        case 'B':
            type = SOFT|HARD;
            break;
        case 'P':
            if (!isdigit(*optarg) || (pid = atoi(optarg)) < 0) {
                warnx("invalid pid `%s'", optarg);
                usage();
            }
            break;
        default:
        case ':': /* Without arg */
            if ((p = strchr(rcs_string, optopt)) != NULL) {
                int rcswhich1 = p - rcs_string;
                if (optarg && *optarg == '-') { /* 'arg' is actually a switch */
                    --optind;           /* back one arg, and make arg NULL */
                    optarg = NULL;
                }
                todo = optarg == NULL ? RCSSEL : RCSSET;
                if (type == ANY)
                    type = BOTH;
                which_limits[rcswhich1] = optarg ? type : DISPLAYONLY;
                set_limits[rcswhich1] = resource_num(rcswhich1, optopt, optarg);
                num_limits++;
                break;
            }
            /* FALLTHRU */
        case '?':
            usage();
        }
        optarg = NULL;
    }

    if (pid != -1) {
        if (cls != NULL) {
            warnx("-C cannot be used with -P option");
            usage();
        }
        if (pwd != NULL) {
            warnx("-U cannot be used with -P option");
            usage();
        }
    }

    /* Get current resource values */
    setproc = 0;
    for (i = 0; i < RLIM_NLIMITS; i++) {
        if (pid == -1) {
            getrlimit(i, &limits[i]);
        } else if (doall || num_limits == 0) {
            getrlimit_proc(pid, i, &limits[i]);
        } else if (which_limits[i] != 0) {
            getrlimit_proc(pid, i, &limits[i]);
            setproc = 1;
        }
    }

    /* If user was specified, get class from that */
    if (pwd != NULL)
        lc = login_getpwclass(pwd);
    else if (cls != NULL && *cls != '\0') {
        lc = login_getclassbyname(cls, NULL);
        if (lc == NULL || strcmp(cls, lc->lc_class) != 0)
            fprintf(stderr, "login class '%s' non-existent, using %s\n",
                    cls, lc?lc->lc_class:"current settings");
    }

    /* If we have a login class, update resource table from that */
    if (lc != NULL) {
        for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
            char str[40];
            rlim_t val;

            /* current value overridden by resourcename or resourcename-cur */
            sprintf(str, "%s-cur", resources[rcswhich].cap);
            val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_cur, limits[rcswhich].rlim_cur);
            limits[rcswhich].rlim_cur = resources[rcswhich].func(lc, str, val, val);
            /* maximum value overridden by resourcename or resourcename-max */
            sprintf(str, "%s-max", resources[rcswhich].cap);
            val = resources[rcswhich].func(lc, resources[rcswhich].cap, limits[rcswhich].rlim_max, limits[rcswhich].rlim_max);
            limits[rcswhich].rlim_max = resources[rcswhich].func(lc, str, val, val);
        }
    }

    /* now, let's determine what we wish to do with all this */

    argv += optind;

    /* If we're setting limits or doing an eval (ie. we're not just
     * displaying), then check that hard limits are not lower than
     * soft limits, and force rasing the hard limit if we need to if
     * we are raising the soft limit, or lower the soft limit if we
     * are lowering the hard limit.
     */
    if ((*argv || doeval) && getuid() == 0) {

        for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
            if (limits[rcswhich].rlim_max != RLIM_INFINITY) {
                if (limits[rcswhich].rlim_cur == RLIM_INFINITY) {
                    limits[rcswhich].rlim_max = RLIM_INFINITY;
                    which_limits[rcswhich] |= HARD;
                } else if (limits[rcswhich].rlim_cur > limits[rcswhich].rlim_max) {
                    if (which_limits[rcswhich] == SOFT) {
                        limits[rcswhich].rlim_max = limits[rcswhich].rlim_cur;
                        which_limits[rcswhich] |= HARD;
                    }  else if (which_limits[rcswhich] == HARD) {
                        limits[rcswhich].rlim_cur = limits[rcswhich].rlim_max;
                        which_limits[rcswhich] |= SOFT;
                    } else {
                        /* else.. if we're specifically setting both to
                         * silly values, then let it error out.
                         */
                    }
                }
            }
        }
    }

    /* See if we've overridden anything specific on the command line */
    if (num_limits && todo == RCSSET) {
        for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
            if (which_limits[rcswhich] & HARD)
                limits[rcswhich].rlim_max = set_limits[rcswhich];
            if (which_limits[rcswhich] & SOFT)
                limits[rcswhich].rlim_cur = set_limits[rcswhich];
        }
    }

    /* If *argv is not NULL, then we are being asked to
     * (perhaps) set environment variables and run a program
     */
    if (*argv) {
        if (doeval) {
            warnx("-e cannot be used with `cmd' option");
            usage();
        }
        if (pid != -1) {
            warnx("-P cannot be used with `cmd' option");
            usage();
        }

        login_close(lc);

        /* set leading environment variables, like eval(1) */
        while (*argv && (p = strchr(*argv, '='))) {
                *p = '\0';
                rtrn = setenv(*argv++, p + 1, 1);
                *p = '=';
                if (rtrn == -1)
                        err(EXIT_FAILURE, "setenv %s", *argv);
        }

        /* Set limits */
        for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
            if (doall || num_limits == 0 || which_limits[rcswhich] != 0)
                if (setrlimit(rcswhich, &limits[rcswhich]) == -1)
                    err(1, "setrlimit %s", resources[rcswhich].cap);
        }

        if (*argv == NULL)
            usage();

        execvp(*argv, argv);
        err(1, "%s", *argv);
    }

    if (setproc) {
        for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
            if (which_limits[rcswhich] != 0)
                setrlimit_proc(pid, rcswhich, &limits[rcswhich]);
        }
        exit(EXIT_SUCCESS);
    }

    shelltype = doeval ? getshelltype() : SH_NONE;

    if (type == ANY) /* Default to soft limits */
        type = SOFT;

    /* Display limits */
    printf(shellparm[shelltype].cmd,
           lc ? " for class " : " (current)",
           lc ? lc->lc_class : "");

    for (rcswhich = 0; rcswhich < RLIM_NLIMITS; rcswhich++) {
        if (doall || num_limits == 0 || which_limits[rcswhich] != 0) {
            if (which_limits[rcswhich] == ANY)
                which_limits[rcswhich] = type;
            if (shellparm[shelltype].lprm[rcswhich].pfx) {
                if (shellparm[shelltype].both && limits[rcswhich].rlim_cur == limits[rcswhich].rlim_max) {
                    print_limit(limits[rcswhich].rlim_max,
                                shellparm[shelltype].lprm[rcswhich].divisor,
                                shellparm[shelltype].inf,
                                shellparm[shelltype].lprm[rcswhich].pfx,
                                shellparm[shelltype].lprm[rcswhich].sfx,
                                shellparm[shelltype].both);
                } else {
                    if (which_limits[rcswhich] & HARD) {
                        print_limit(limits[rcswhich].rlim_max,
                                    shellparm[shelltype].lprm[rcswhich].divisor,
                                    shellparm[shelltype].inf,
                                    shellparm[shelltype].lprm[rcswhich].pfx,
                                    shellparm[shelltype].lprm[rcswhich].sfx,
                                    shellparm[shelltype].hard);
                    }
                    if (which_limits[rcswhich] & SOFT) {
                        print_limit(limits[rcswhich].rlim_cur,
                                    shellparm[shelltype].lprm[rcswhich].divisor,
                                    shellparm[shelltype].inf,
                                    shellparm[shelltype].lprm[rcswhich].pfx,
                                    shellparm[shelltype].lprm[rcswhich].sfx,
                                    shellparm[shelltype].soft);
                    }
                }
            }
        }
    }

    login_close(lc);
    exit(EXIT_SUCCESS);
}


static void
usage(void)
{
    (void)fprintf(stderr,
        "usage: limits [-C class|-P pid|-U user] [-eaSHBE] "
        "[-bcdfklmnostuVvpwy [val]] [[name=val ...] cmd]\n");
    exit(EXIT_FAILURE);
}

static void
print_limit(rlim_t limit, unsigned divisor, const char * inf, const char * pfx, const char * sfx, const char * which)
{
    char numbr[64];

    if (limit == RLIM_INFINITY)
        strlcpy(numbr, inf, sizeof(numbr));
    else
        sprintf(numbr, "%jd", (intmax_t)((limit + divisor/2) / divisor));
    printf(pfx, which, numbr);
    printf(sfx, which);

}


static rlim_t
resource_num(int which, int ch, const char *str)
{
    rlim_t res = RLIM_INFINITY;

    if (str != NULL &&
        !(strcasecmp(str, "inf") == 0 ||
          strcasecmp(str, "infinity") == 0 ||
          strcasecmp(str, "unlimit") == 0 ||
          strcasecmp(str, "unlimited") == 0)) {
        const char * s = str;
        char *e;

        switch (which) {
        case RLIMIT_CPU:        /* time values */
            errno = 0;
            res = 0;
            while (*s) {
                rlim_t tim = strtoq(s, &e, 0);
                if (e == NULL || e == s || errno)
                    break;
                switch (*e++) {
                case 0:                 /* end of string */
                    e--;
                default:
                case 's': case 'S':     /* seconds */
                    break;
                case 'm': case 'M':     /* minutes */
                    tim *= 60L;
                    break;
                case 'h': case 'H':     /* hours */
                    tim *= (60L * 60L);
                    break;
                case 'd': case 'D':     /* days */
                    tim *= (60L * 60L * 24L);
                    break;
                case 'w': case 'W':     /* weeks */
                    tim *= (60L * 60L * 24L * 7L);
                    break;
                case 'y': case 'Y':     /* Years */
                    tim *= (60L * 60L * 24L * 365L);
                }
                s = e;
                res += tim;
            }
            break;
        case RLIMIT_FSIZE: /* Size values */
        case RLIMIT_DATA:
        case RLIMIT_STACK:
        case RLIMIT_CORE:
        case RLIMIT_RSS:
        case RLIMIT_MEMLOCK:
        case RLIMIT_SBSIZE:
        case RLIMIT_VMEM:
        case RLIMIT_SWAP:
        case RLIMIT_PIPEBUF:
            errno = 0;
            res = 0;
            while (*s) {
                rlim_t mult, tim = strtoq(s, &e, 0);
                if (e == NULL || e == s || errno)
                    break;
                switch (*e++) {
                case 0: /* end of string */
                    e--;
                default:
                    mult = 1;
                    break;
                case 'b': case 'B':     /* 512-byte blocks */
                    mult = 512;
                    break;
                case 'k': case 'K':     /* 1024-byte Kilobytes */
                    mult = 1024;
                    break;
                case 'm': case 'M':     /* 1024-k kbytes */
                    mult = 1024 * 1024;
                    break;
                case 'g': case 'G':     /* 1Gbyte */
                    mult = 1024 * 1024 * 1024;
                    break;
                case 't': case 'T':     /* 1TBte */
                    mult = 1024LL * 1024LL * 1024LL * 1024LL;
                    break;
                }
                s = e;
                res += (tim * mult);
            }
            break;
        case RLIMIT_NPROC:
        case RLIMIT_NOFILE:
        case RLIMIT_NPTS:
        case RLIMIT_KQUEUES:
        case RLIMIT_UMTXP:
        case RLIMIT_VMM:
            res = strtoq(s, &e, 0);
            s = e;
            break;
        }
        if (*s) {
            warnx("invalid value -%c `%s'", ch, str);
            usage();
        }
    }
    return res;
}


static int
getshellbyname(const char * shell)
{
    int i;
    const char * q;
    const char * p = strrchr(shell, '/');

    p = p ? p+1 : shell;
    for (i = 0; (q = shellparm[i].name) != NULL; i++) {
        while (*q) {
            int j = strcspn(q, "|");

            if (j == 0)
                break;
            if (strncmp(p, q, j) == 0)
                return i;
            if (*(q += j))
                ++q;
        }
    }
    return SH_SH;
}


/*
 * Determine the type of shell our parent process is
 * This is quite tricky, not 100% reliable and probably
 * not nearly as thorough as it should be. Basically, this
 * is a "best guess" only, but hopefully will work in
 * most cases.
 */

static int
getshelltype(void)
{
    pid_t ppid = getppid();

    if (ppid != 1) {
        struct kinfo_proc kp;
        struct stat st;
        char path[MAXPATHLEN];
        char * shell = getenv("SHELL");
        int mib[4];
        size_t len;

        mib[0] = CTL_KERN;
        mib[1] = KERN_PROC;
        mib[3] = ppid;

        if (shell != NULL && stat(shell, &st) != -1) {
            struct stat st1;

            mib[2] = KERN_PROC_PATHNAME;
            len = sizeof(path);
            if (sysctl(mib, 4, path, &len, NULL, 0) != -1) {
                /* $SHELL is actual shell? */
                if (stat(path, &st1) != -1 && memcmp(&st, &st1, sizeof st) == 0)
                    return getshellbyname(shell);
            }
        }
        mib[2] = KERN_PROC_PID;
        len = sizeof(kp);
        if (sysctl(mib, 4, &kp, &len, NULL, 0) != -1)
            return getshellbyname(kp.ki_comm);
    }
    return SH_SH;
}

static void
getrlimit_proc(pid_t pid, int resource, struct rlimit *rlp)
{
    int error;
    int name[5];
    size_t len;

    name[0] = CTL_KERN;
    name[1] = KERN_PROC;
    name[2] = KERN_PROC_RLIMIT;
    name[3] = pid;
    name[4] = resource;
    len = sizeof(*rlp);
    error = sysctl(name, 5, rlp, &len, NULL, 0);
    if (error == -1)
        err(EXIT_FAILURE, "sysctl: kern.proc.rlimit: %d", pid);
    if (len != sizeof(*rlp))
        errx(EXIT_FAILURE, "sysctl() returns wrong size");
}

static void
setrlimit_proc(pid_t pid, int resource, const struct rlimit *rlp)
{
    int error;
    int name[5];

    name[0] = CTL_KERN;
    name[1] = KERN_PROC;
    name[2] = KERN_PROC_RLIMIT;
    name[3] = pid;
    name[4] = resource;
    error = sysctl(name, 5, NULL, 0, rlp, sizeof(*rlp));
    if (error == -1)
        err(EXIT_FAILURE, "sysctl: kern.proc.rlimit: %d", pid);
}