cmd-inet/usr.bin/finger.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * This is a finger program.  It prints out useful information about users
 * by digging it up from various system files.
 *
 * There are three output formats, all of which give login name, teletype
 * line number, and login time.  The short output format is reminiscent
 * of finger on ITS, and gives one line of information per user containing
 * in addition to the minimum basic requirements (MBR), the user's full name,
 * idle time and location.
 * The quick style output is UNIX who-like, giving only name, teletype and
 * login time.  Finally, the long style output give the same information
 * as the short (in more legible format), the home directory and shell
 * of the user, and, if it exits, a copy of the file .plan in the users
 * home directory.  Finger may be called with or without a list of people
 * to finger -- if no list is given, all the people currently logged in
 * are fingered.
 *
 * The program is validly called by one of the following:
 *
 *  finger          {short form list of users}
 *  finger -l       {long form list of users}
 *  finger -b       {briefer long form list of users}
 *  finger -q       {quick list of users}
 *  finger -i       {quick list of users with idle times}
 *  finger -m       {matches arguments against only username}
 *  finger -f       {suppress header in non-long form}
 *  finger -p       {suppress printing of .plan file}
 *  finger -h       {suppress printing of .project file}
 *  finger -i       {forces "idle" output format}
 *  finger namelist     {long format list of specified users}
 *  finger -s namelist  {short format list of specified users}
 *  finger -w namelist  {narrow short format list of specified users}
 *
 * where 'namelist' is a list of users login names.
 * The other options can all be given after one '-', or each can have its
 * own '-'.  The -f option disables the printing of headers for short and
 * quick outputs.  The -b option briefens long format outputs.  The -p
 * option turns off plans for long format outputs.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <utmpx.h>
#include <sys/signal.h>
#include <pwd.h>
#include <stdio.h>
#include <lastlog.h>
#include <ctype.h>
#include <sys/time.h>
#include <time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <locale.h>
#include <sys/select.h>
#include <stdlib.h>
#include <strings.h>
#include <fcntl.h>
#include <curses.h>
#include <unctrl.h>
#include <maillock.h>
#include <deflt.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <macros.h>

static char gecos_ignore_c = '*';   /* ignore this in real name */
static char gecos_sep_c = ',';      /* separator in pw_gecos field */
static char gecos_samename = '&';   /* repeat login name in real name */

#define TALKABLE    0220        /* tty is writable if this mode */

#define NMAX    sizeof (((struct utmpx *)0)->ut_name)
#define LMAX    sizeof (((struct utmpx *)0)->ut_line)
#define HMAX    sizeof (((struct utmpx *)0)->ut_host)

struct person {             /* one for each person fingered */
    char *name;         /* name */
    char tty[LMAX+1];       /* null terminated tty line */
    char host[HMAX+1];      /* null terminated remote host name */
    char *ttyloc;           /* location of tty line, if any */
    time_t loginat;         /* time of (last) login */
    time_t idletime;        /* how long idle (if logged in) */
    char *realname;         /* pointer to full name */
    struct passwd *pwd;     /* structure of /etc/passwd stuff */
    char loggedin;          /* person is logged in */
    char writable;          /* tty is writable */
    char original;          /* this is not a duplicate entry */
    struct person *link;        /* link to next person */
};

char LASTLOG[] = "/var/adm/lastlog";    /* last login info */
char PLAN[] = "/.plan";         /* what plan file is */
char PROJ[] = "/.project";      /* what project file */

int unbrief = 1;            /* -b option default */
int header = 1;             /* -f option default */
int hack = 1;               /* -h option default */
int idle = 0;               /* -i option default */
int large = 0;              /* -l option default */
int match = 1;              /* -m option default */
int plan = 1;               /* -p option default */
int unquick = 1;            /* -q option default */
int small = 0;              /* -s option default */
int wide = 1;               /* -w option default */

/*
 * RFC 1288 says that system administrators should have the option of
 * separately allowing ASCII characters less than 32 or greater than
 * 126.  The termpass variable keeps track of this.
 */
char    defaultfile[] = "/etc/default/finger";
char    passvar[] = "PASS=";
int termpass = 0;           /* default is ASCII only */
char *termopts[] = {
#define TERM_LOW    0
    "low",
#define TERM_HIGH   1
    "high",
    (char *)NULL
};
#define TS_LOW  (1 << TERM_LOW)     /* print characters less than 32 */
#define TS_HIGH (1 << TERM_HIGH)    /* print characters greater than 126 */


int unshort;
FILE *lf;               /* LASTLOG file pointer */
struct person *person1;         /* list of people */
size_t nperson;             /* number of people */
time_t tloc;                /* current time */

char usagestr[] = "Usage: "
    "finger [-bfhilmpqsw] [name1 [name2 ...] ]\n";

int AlreadyPrinted(uid_t uid);
void AnyMail(char *name);
void catfile(char *s, mode_t mode, int trunc_at_nl);
void decode(struct person *pers);
void doall(void);
void donames(char **argv);
void findidle(struct person *pers);
void findwhen(struct person *pers);
void fwclose(void);
void fwopen(void);
void initscreening(void);
void ltimeprint(char *before, time_t *dt, char *after);
int matchcmp(char *gname, char *login, char *given);
int namecmp(char *name1, char *name2);
int netfinger(char *name);
void personprint(struct person *pers);
void print(void);
struct passwd *pwdcopy(const struct passwd *pfrom);
void quickprint(struct person *pers);
void shortprint(struct person *pers);
void stimeprint(time_t *dt);
void sort_by_username(void);


int
main(int argc, char **argv)
{
    int c;

    (void) setlocale(LC_ALL, "");
    /* parse command line for (optional) arguments */
    while ((c = getopt(argc, argv, "bfhilmpqsw")) != EOF)
            switch (c) {
            case 'b':
                unbrief = 0;
                break;
            case 'f':
                header = 0;
                break;
            case 'h':
                hack = 0;
                break;
            case 'i':
                idle = 1;
                unquick = 0;
                break;
            case 'l':
                large = 1;
                break;
            case 'm':
                match = 0;
                break;
            case 'p':
                plan = 0;
                break;
            case 'q':
                unquick = 0;
                break;
            case 's':
                small = 1;
                break;
            case 'w':
                wide = 0;
                break;
            default:
                (void) fprintf(stderr, usagestr);
                exit(1);
            }
    if (unquick || idle)
        tloc = time(NULL);

    /* find out what filtering on .plan/.project files we should do */
    initscreening();

    /*
     * optind == argc means no names given
     */
    if (optind == argc)
        doall();
    else
        donames(&argv[optind]);

    sort_by_username();

    if (nperson > 0)
        print();
    return (0);
    /* NOTREACHED */
}

void
doall(void)
{
    struct person *p;
    struct passwd *pw;
    struct utmpx *u;
    char name[NMAX + 1];

    unshort = large;
    setutxent();
    if (unquick) {
        setpwent();
        fwopen();
    }
    while ((u = getutxent()) != NULL) {
        if (u->ut_name[0] == 0 ||
            nonuserx(*u) ||
            u->ut_type != USER_PROCESS)
            continue;
        if (person1 == NULL)
            p = person1 = malloc(sizeof (*p));
        else {
            p->link = malloc(sizeof (*p));
            p = p->link;
        }
        bcopy(u->ut_name, name, NMAX);
        name[NMAX] = 0;
        bcopy(u->ut_line, p->tty, LMAX);
        p->tty[LMAX] = 0;
        bcopy(u->ut_host, p->host, HMAX);
        p->host[HMAX] = 0;
        p->loginat = u->ut_tv.tv_sec;
        p->pwd = NULL;
        p->loggedin = 1;
        if (unquick && (pw = getpwnam(name))) {
            p->pwd = pwdcopy(pw);
            decode(p);
            p->name = p->pwd->pw_name;
        } else
            p->name = strdup(name);
        p->ttyloc = NULL;

        nperson++;
    }
    if (unquick) {
        fwclose();
        endpwent();
    }
    endutxent();
    if (nperson == 0) {
        (void) printf("No one logged on\n");
        return;
    }
    p->link = NULL;
}

void
donames(char **argv)
{
    struct person   *p;
    struct passwd   *pw;
    struct utmpx    *u;

    /*
     * get names from command line and check to see if they're
     * logged in
     */
    unshort = !small;
    for (; *argv != NULL; argv++) {
        if (netfinger(*argv))
            continue;
        if (person1 == NULL)
            p = person1 = malloc(sizeof (*p));
        else {
            p->link = malloc(sizeof (*p));
            p = p->link;
        }
        p->name = *argv;
        p->loggedin = 0;
        p->original = 1;
        p->pwd = NULL;

        nperson++;
    }
    if (nperson == 0)
        return;
    p->link = NULL;
    /*
     * if we are doing it, read /etc/passwd for the useful info
     */
    if (unquick) {
        setpwent();
        if (!match) {
            for (p = person1; p != NULL; p = p->link) {
                if ((pw = getpwnam(p->name)) != NULL)
                    p->pwd = pwdcopy(pw);
            }
        } else {
            while ((pw = getpwent()) != NULL) {
                for (p = person1; p != NULL; p = p->link) {
                    if (!p->original)
                        continue;
                    if (strcmp(p->name, pw->pw_name) != 0 &&
                        !matchcmp(pw->pw_gecos, pw->pw_name,
                        p->name)) {
                        continue;
                    }
                    if (p->pwd == NULL) {
                        p->pwd = pwdcopy(pw);
                    } else {
                        struct person *new;
                        /*
                         * Handle multiple login names.
                         * Insert new "duplicate" entry
                         * behind.
                         */
                        new = malloc(sizeof (*new));
                        new->pwd = pwdcopy(pw);
                        new->name = p->name;
                        new->original = 1;
                        new->loggedin = 0;
                        new->ttyloc = NULL;
                        new->link = p->link;
                        p->original = 0;
                        p->link = new;
                        p = new;

                        nperson++;
                    }
                }
            }
        }
        endpwent();
    }
    /* Now get login information */
    setutxent();
    while ((u = getutxent()) != NULL) {
        if (u->ut_name[0] == 0 || u->ut_type != USER_PROCESS)
            continue;
        for (p = person1; p != NULL; p = p->link) {
            p->ttyloc = NULL;
            if (p->loggedin == 2)
                continue;
            if (strncmp((p->pwd != NULL) ?
                p->pwd->pw_name : p->name,
                u->ut_name, NMAX) != 0)
                continue;
            if (p->loggedin == 0) {
                bcopy(u->ut_line, p->tty, LMAX);
                p->tty[LMAX] = 0;
                bcopy(u->ut_host, p->host, HMAX);
                p->host[HMAX] = 0;
                p->loginat = u->ut_tv.tv_sec;
                p->loggedin = 1;
            } else {    /* p->loggedin == 1 */
                struct person *new;
                new = malloc(sizeof (*new));
                new->name = p->name;
                bcopy(u->ut_line, new->tty, LMAX);
                new->tty[LMAX] = 0;
                bcopy(u->ut_host, new->host, HMAX);
                new->host[HMAX] = 0;
                new->loginat = u->ut_tv.tv_sec;
                new->pwd = p->pwd;
                new->loggedin = 1;
                new->original = 0;
                new->link = p->link;
                p->loggedin = 2;
                p->link = new;
                p = new;

                nperson++;
            }
        }
    }
    endutxent();
    if (unquick) {
        fwopen();
        for (p = person1; p != NULL; p = p->link)
            decode(p);
        fwclose();
    }
}

void
print(void)
{
    struct person *p;
    char *s;

    /*
     * print out what we got
     */
    if (header) {
        if (unquick) {
            if (!unshort) {
                if (wide) {
                    (void) printf("Login       "
                        "Name               TTY         "
                        "Idle    When    Where\n");
                } else {
                    (void) printf("Login    TTY Idle    "
                        "When    Where\n");
                }
            }
        } else {
            (void) printf("Login      TTY                When");
            if (idle)
                (void) printf("             Idle");
            (void) putchar('\n');
        }
    }
    for (p = person1; p != NULL; p = p->link) {
        if (!unquick) {
            quickprint(p);
            continue;
        }
        if (!unshort) {
            shortprint(p);
            continue;
        }
        personprint(p);
        if (p->pwd != NULL && !AlreadyPrinted(p->pwd->pw_uid)) {
            AnyMail(p->pwd->pw_name);
            if (hack) {
                struct stat sbuf;

                s = malloc(strlen(p->pwd->pw_dir) +
                    sizeof (PROJ));
                if (s != NULL) {
                    (void) strcpy(s, p->pwd->pw_dir);
                    (void) strcat(s, PROJ);
                    if (stat(s, &sbuf) != -1 &&
                        (S_ISREG(sbuf.st_mode) ||
                        S_ISFIFO(sbuf.st_mode)) &&
                        (sbuf.st_mode & S_IROTH)) {
                        (void) printf("Project: ");
                        catfile(s, sbuf.st_mode, 1);
                        (void) putchar('\n');
                    }
                    free(s);
                }
            }
            if (plan) {
                struct stat sbuf;

                s = malloc(strlen(p->pwd->pw_dir) +
                    sizeof (PLAN));
                if (s != NULL) {
                    (void) strcpy(s, p->pwd->pw_dir);
                    (void) strcat(s, PLAN);
                    if (stat(s, &sbuf) == -1 ||
                        (!S_ISREG(sbuf.st_mode) &&
                        !S_ISFIFO(sbuf.st_mode)) ||
                        ((sbuf.st_mode & S_IROTH) == 0))
                        (void) printf("No Plan.\n");
                    else {
                        (void) printf("Plan:\n");
                        catfile(s, sbuf.st_mode, 0);
                    }
                    free(s);
                }
            }
        }
        if (p->link != NULL)
            (void) putchar('\n');
    }
}

/*
 * Duplicate a pwd entry.
 * Note: Only the useful things (what the program currently uses) are copied.
 */
struct passwd *
pwdcopy(const struct passwd *pfrom)
{
    struct passwd *pto;

    pto = malloc(sizeof (*pto));
    pto->pw_name = strdup(pfrom->pw_name);
    pto->pw_uid = pfrom->pw_uid;
    pto->pw_gecos = strdup(pfrom->pw_gecos);
    pto->pw_dir = strdup(pfrom->pw_dir);
    pto->pw_shell = strdup(pfrom->pw_shell);
    return (pto);
}

/*
 * print out information on quick format giving just name, tty, login time
 * and idle time if idle is set.
 */
void
quickprint(struct person *pers)
{
    (void) printf("%-8.8s  ", pers->name);
    if (pers->loggedin) {
        if (idle) {
            findidle(pers);
            (void) printf("%c%-12s %-16.16s",
                pers->writable ? ' ' : '*',
                pers->tty, ctime(&pers->loginat));
            ltimeprint("   ", &pers->idletime, "");
        } else {
            (void) printf(" %-12s %-16.16s",
                pers->tty, ctime(&pers->loginat));
        }
        (void) putchar('\n');
    } else {
        (void) printf("          Not Logged In\n");
    }
}

/*
 * print out information in short format, giving login name, full name,
 * tty, idle time, login time, and host.
 */
void
shortprint(struct person *pers)
{
    char *p;

    if (pers->pwd == NULL) {
        (void) printf("%-15s       ???\n", pers->name);
        return;
    }
    (void) printf("%-8s", pers->pwd->pw_name);
    if (wide) {
        if (pers->realname != NULL) {
            (void) printf(" %-20.20s", pers->realname);
        } else {
            (void) printf("        ???          ");
        }
    }
    (void) putchar(' ');
    if (pers->loggedin && !pers->writable) {
        (void) putchar('*');
    } else {
        (void) putchar(' ');
    }
    if (*pers->tty) {
        (void) printf("%-11.11s ", pers->tty);
    } else {
        (void) printf("            ");  /* 12 spaces */
    }
    p = ctime(&pers->loginat);
    if (pers->loggedin) {
        stimeprint(&pers->idletime);
        (void) printf(" %3.3s %-5.5s ", p, p + 11);
    } else if (pers->loginat == 0) {
        (void) printf(" < .  .  .  . >");
    } else if (tloc - pers->loginat >= 180 * 24 * 60 * 60) {
        (void) printf(" <%-6.6s, %-4.4s>", p + 4, p + 20);
    } else {
        (void) printf(" <%-12.12s>", p + 4);
    }
    if (*pers->host) {
        (void) printf(" %-20.20s", pers->host);
    } else {
        if (pers->ttyloc != NULL)
            (void) printf(" %-20.20s", pers->ttyloc);
    }
    (void) putchar('\n');
}


/*
 * print out a person in long format giving all possible information.
 * directory and shell are inhibited if unbrief is clear.
 */
void
personprint(struct person *pers)
{
    if (pers->pwd == NULL) {
        (void) printf("Login name: %-10s\t\t\tIn real life: ???\n",
            pers->name);
        return;
    }
    (void) printf("Login name: %-10s", pers->pwd->pw_name);
    if (pers->loggedin && !pers->writable) {
        (void) printf(" (messages off)  ");
    } else {
        (void) printf("         ");
    }
    if (pers->realname != NULL) {
        (void) printf("In real life: %s", pers->realname);
    }
    if (unbrief) {
        (void) printf("\nDirectory: %-25s", pers->pwd->pw_dir);
        if (*pers->pwd->pw_shell)
            (void) printf("\tShell: %-s", pers->pwd->pw_shell);
    }
    if (pers->loggedin) {
        char *ep = ctime(&pers->loginat);
        if (*pers->host) {
            (void) printf("\nOn since %15.15s on %s from %s",
                &ep[4], pers->tty, pers->host);
            ltimeprint("\n", &pers->idletime, " Idle Time");
        } else {
            (void) printf("\nOn since %15.15s on %-12s",
                &ep[4], pers->tty);
            ltimeprint("\n", &pers->idletime, " Idle Time");
        }
    } else if (pers->loginat == 0) {
        (void) printf("\nNever logged in.");
    } else if (tloc - pers->loginat > 180 * 24 * 60 * 60) {
        char *ep = ctime(&pers->loginat);
        (void) printf("\nLast login %10.10s, %4.4s on %s",
            ep, ep+20, pers->tty);
        if (*pers->host) {
            (void) printf(" from %s", pers->host);
        }
    } else {
        char *ep = ctime(&pers->loginat);
        (void) printf("\nLast login %16.16s on %s", ep, pers->tty);
        if (*pers->host) {
            (void) printf(" from %s", pers->host);
        }
    }
    (void) putchar('\n');
}


/*
 * decode the information in the gecos field of /etc/passwd
 */
void
decode(struct person *pers)
{
    char buffer[256];
    char *bp, *gp, *lp;

    pers->realname = NULL;
    if (pers->pwd == NULL)
        return;
    gp = pers->pwd->pw_gecos;
    bp = buffer;

    if (gecos_ignore_c != '\0' &&
        *gp == gecos_ignore_c) {
        gp++;
    }
    while (*gp != '\0' &&
        *gp != gecos_sep_c) {           /* name */
        if (*gp == gecos_samename) {
            lp = pers->pwd->pw_name;
            if (islower(*lp))
                *bp++ = toupper(*lp++);
            while (*bp++ = *lp++)
                ;
            bp--;
            gp++;
        } else {
            *bp++ = *gp++;
        }
    }
    *bp++ = 0;
    if (bp > (buffer + 1))
        pers->realname = strdup(buffer);
    if (pers->loggedin)
        findidle(pers);
    else
        findwhen(pers);
}

/*
 * find the last log in of a user by checking the LASTLOG file.
 * the entry is indexed by the uid, so this can only be done if
 * the uid is known (which it isn't in quick mode)
 */
void
fwopen(void)
{
    if ((lf = fopen(LASTLOG, "r")) == NULL)
        (void) fprintf(stderr, "finger: %s open error\n", LASTLOG);
}

void
findwhen(struct person *pers)
{
    struct lastlog ll;

    if (lf != NULL) {
        if (fseeko(lf, (off_t)pers->pwd->pw_uid * (off_t)sizeof (ll),
            SEEK_SET) == 0) {
            if (fread((char *)&ll, sizeof (ll), 1, lf) == 1) {
                int l_max, h_max;

                l_max = min(LMAX, sizeof (ll.ll_line));
                h_max = min(HMAX, sizeof (ll.ll_host));

                bcopy(ll.ll_line, pers->tty, l_max);
                pers->tty[l_max] = '\0';
                bcopy(ll.ll_host, pers->host, h_max);
                pers->host[h_max] = '\0';
                pers->loginat = ll.ll_time;
            } else {
                if (ferror(lf))
                    (void) fprintf(stderr,
                        "finger: %s read error\n", LASTLOG);
                pers->tty[0] = 0;
                pers->host[0] = 0;
                pers->loginat = 0L;
            }
        } else {
            (void) fprintf(stderr, "finger: %s fseeko error\n",
                LASTLOG);
        }
    } else {
        pers->tty[0] = 0;
        pers->host[0] = 0;
        pers->loginat = 0L;
    }
}

void
fwclose(void)
{
    if (lf != NULL)
        (void) fclose(lf);
}

/*
 * find the idle time of a user by doing a stat on /dev/tty??,
 * where tty?? has been gotten from UTMPX_FILE, supposedly.
 */
void
findidle(struct person *pers)
{
    struct stat ttystatus;
    struct stat inputdevstatus;
#define TTYLEN (sizeof ("/dev/") - 1)
    static char buffer[TTYLEN + LMAX + 1] = "/dev/";
    time_t t;
    time_t lastinputtime;

    (void) strcpy(buffer + TTYLEN, pers->tty);
    buffer[TTYLEN+LMAX] = 0;
    if (stat(buffer, &ttystatus) < 0) {
        (void) fprintf(stderr, "finger: Can't stat %s\n", buffer);
        exit(4);
    }
    lastinputtime = ttystatus.st_atime;
    if (strcmp(pers->tty, "console") == 0) {
        /*
         * On the console, the user may be running a window system; if
         * so, their activity will show up in the last-access times of
         * "/dev/kbd" and "/dev/mouse", so take the minimum of the idle
         * times on those two devices and "/dev/console" and treat that
         * as the idle time.
         */
        if (stat("/dev/kbd", &inputdevstatus) == 0) {
            if (lastinputtime < inputdevstatus.st_atime)
                lastinputtime = inputdevstatus.st_atime;
        }
        if (stat("/dev/mouse", &inputdevstatus) == 0) {
            if (lastinputtime < inputdevstatus.st_atime)
                lastinputtime = inputdevstatus.st_atime;
        }
    }
    t = time(NULL);
    if (t < lastinputtime)
        pers->idletime = (time_t)0;
    else
        pers->idletime = t - lastinputtime;
    pers->writable = (ttystatus.st_mode & TALKABLE) == TALKABLE;
}

/*
 * print idle time in short format; this program always prints 4 characters;
 * if the idle time is zero, it prints 4 blanks.
 */
void
stimeprint(time_t *dt)
{
    struct tm *delta;

    delta = gmtime(dt);
    if (delta->tm_yday == 0)
        if (delta->tm_hour == 0)
            if (delta->tm_min == 0)
                (void) printf("    ");
            else
                (void) printf("  %2d", delta->tm_min);
        else
            if (delta->tm_hour >= 10)
                (void) printf("%3d:", delta->tm_hour);
            else
                (void) printf("%1d:%02d",
                    delta->tm_hour, delta->tm_min);
    else
        (void) printf("%3dd", delta->tm_yday);
}

/*
 * print idle time in long format with care being taken not to pluralize
 * 1 minutes or 1 hours or 1 days.
 * print "prefix" first.
 */
void
ltimeprint(char *before, time_t *dt, char *after)
{
    struct tm *delta;

    delta = gmtime(dt);
    if (delta->tm_yday == 0 && delta->tm_hour == 0 && delta->tm_min == 0 &&
        delta->tm_sec <= 10)
        return;
    (void) printf("%s", before);
    if (delta->tm_yday >= 10)
        (void) printf("%d days", delta->tm_yday);
    else if (delta->tm_yday > 0)
        (void) printf("%d day%s %d hour%s",
            delta->tm_yday, delta->tm_yday == 1 ? "" : "s",
            delta->tm_hour, delta->tm_hour == 1 ? "" : "s");
    else
        if (delta->tm_hour >= 10)
            (void) printf("%d hours", delta->tm_hour);
        else if (delta->tm_hour > 0)
            (void) printf("%d hour%s %d minute%s",
                delta->tm_hour, delta->tm_hour == 1 ? "" : "s",
                delta->tm_min, delta->tm_min == 1 ? "" : "s");
        else
            if (delta->tm_min >= 10)
                (void) printf("%2d minutes", delta->tm_min);
            else if (delta->tm_min == 0)
                (void) printf("%2d seconds", delta->tm_sec);
            else
                (void) printf("%d minute%s %d second%s",
                    delta->tm_min,
                    delta->tm_min == 1 ? "" : "s",
                    delta->tm_sec,
                    delta->tm_sec == 1 ? "" : "s");
    (void) printf("%s", after);
}

/*
 * The grammar of the pw_gecos field is sufficiently complex that the
 * best way to parse it is by using an explicit finite-state machine,
 * in which a table defines the rules of interpretation.
 *
 * Some special rules are necessary to handle the fact that names
 * may contain certain punctuation characters.  At this writing,
 * the possible punctuation characters are '.', '-', and '_'.
 *
 * Other rules are needed to account for characters that require special
 * processing when they appear in the pw_gecos field.  At present, there
 * are three such characters, with these default values and effects:
 *
 *    gecos_ignore_c   '*'    This character is ignored.
 *    gecos_sep_c      ','    Delimits displayed and nondisplayed contents.
 *    gecos_samename   '&'    Copies the login name into the output.
 *
 * As the program examines each successive character in the returned
 * pw_gecos value, it fetches (from the table) the FSM rule applicable
 * for that character in the current machine state, and thus determines
 * the next state.
 *
 * The possible states are:
 *    S0 start
 *    S1 in a word
 *    S2 not in a word
 *    S3 copy login name into output
 *    S4 end of GECOS field
 *
 * Here follows a depiction of the state transitions.
 *
 *
 *              gecos_ignore_c OR isspace OR any other character
 *                  +--+
 *                  |  |
 *                  |  V
 *                 +-----+
 *    NULL OR      | S0  |  isalpha OR isdigit
 * +---------------|start|------------------------+
 * |  gecos_sep_c  +-----+                        |     isalpha OR isdigit
 * |                |  |                          |   +---------------------+
 * |                |  |                          |   | OR '.' '-' '_'      |
 * |                |  |isspace                   |   |                     |
 * |                |  +-------+                  V   V                     |
 * |                |          |              +-----------+                 |
 * |                |          |              |    S1     |<--+             |
 * |                |          |              | in a word |   | isalpha OR  |
 * |                |          |              +-----------+   | isdigit OR  |
 * |                |          |               |  |  |  |     | '.' '-' '_' |
 * |                |    +----- ---------------+  |  |  +-----+             |
 * |                |    |     |                  |  |                      |
 * |                |    |     |   gecos_ignore_c |  |                      |
 * |                |    |     |   isspace        |  |                      |
 * |                |    |     |   ispunct/other  |  |                      |
 * |                |    |     |   any other char |  |                      |
 * |                |    |     |  +---------------+  |                      |
 * |                |    |     |  |                  |NULL OR gecos_sep_c   |
 * |                |    |     |  |                  +------------------+   |
 * |  gecos_samename|    |     V  V                                     |   |
 * |  +-------------+    |    +---------------+                         |   |
 * |  |                  |    |       S2      | isspace OR '.' '-' '_'  |   |
 * |  |  gecos_samename  |    | not in a word |<---------------------+  |   |
 * |  |  +---------------+    +---------------+ OR gecos_ignore_c    |  |   |
 * |  |  |                        |    ^  |  |  OR ispunct OR other  |  |   |
 * |  |  |                        |    |  |  |                       |  |   |
 * |  |  |  gecos_samename        |    |  |  +-----------------------+  |   |
 * |  |  |  +---------------------+    |  |                             |   |
 * |  |  |  |                          |  |                             |   |
 * |  |  |  |            gecos_ignore_c|  | NULL OR gecos_sep_c         |   |
 * |  |  |  |            gecos_samename|  +-----------------------+     |   |
 * |  |  |  |            ispunct/other |                          |     |   |
 * |  V  V  V            isspace       |                          |     |   |
 * | +-----------------+ any other char|                          |     |   |
 * | |      S3         |---------------+  isalpha OR isdigit OR   |     |   |
 * | |insert login name|------------------------------------------ ----- ---+
 * | +-----------------+                  '.' '-' '_'             |     |
 * |                |    NULL OR gecos_sep_c                      |     |
 * |                +------------------------------------------+  |     |
 * |                                                           |  |     |
 * |                                                           V  V     V
 * |                                                         +------------+
 * | NULL OR gecos_sep_c                                     |     S4     |
 * +-------------------------------------------------------->|end of gecos|<--+
 *                                                           +------------+   |
 *                                                                      | all |
 *                                                                      +-----+
 *
 *
 *  The transitions from the above diagram are summarized in
 *  the following table of target states, which is implemented
 *  in code as the gecos_fsm array.
 *
 * Input:
 *        +--gecos_ignore_c
 *        |    +--gecos_sep_c
 *        |    |    +--gecos_samename
 *        |    |    |    +--isalpha
 *        |    |    |    |    +--isdigit
 *        |    |    |    |    |      +--isspace
 *        |    |    |    |    |      |    +--punctuation possible in name
 *        |    |    |    |    |      |    |    +--other punctuation
 *        |    |    |    |    |      |    |    |    +--NULL character
 *        |    |    |    |    |      |    |    |    |    +--any other character
 *        |    |    |    |    |      |    |    |    |    |
 *        V    V    V    V    V      V    V    V    V    V
 * From: ---------------------------------------------------
 * S0   | S0 | S4 | S3 | S1 | S1 |   S0 | S1 | S2 | S4 | S0 |
 * S1   | S2 | S4 | S3 | S1 | S1 |   S2 | S1 | S2 | S4 | S2 |
 * S2   | S2 | S4 | S3 | S1 | S1 |   S2 | S2 | S2 | S4 | S2 |
 * S3   | S2 | S4 | S2 | S1 | S1 |   S2 | S1 | S2 | S4 | S2 |
 * S4   | S4 | S4 | S4 | S4 | S4 |   S4 | S4 | S4 | S4 | S4 |
 *
 */

/*
 * Data types and structures for scanning the pw_gecos field.
 */
typedef enum gecos_state {
    S0,     /* start */
    S1,     /* in a word */
    S2,     /* not in a word */
    S3,     /* copy login */
    S4      /* end of gecos */
} gecos_state_t;

#define GFSM_ROWS 5
#define GFSM_COLS 10

gecos_state_t gecos_fsm[GFSM_ROWS][GFSM_COLS] = {
    {S0, S4, S3, S1, S1,    S0, S1, S2, S4, S0},    /* S0 */
    {S2, S4, S3, S1, S1,    S2, S1, S2, S4, S2},    /* S1 */
    {S2, S4, S3, S1, S1,    S2, S2, S2, S4, S2},    /* S2 */
    {S2, S4, S2, S1, S1,    S2, S1, S2, S4, S2},    /* S3 */
    {S4, S4, S4, S4, S4,    S4, S4, S4, S4, S4} /* S4 */
};

/*
 * Scan the pw_gecos field according to defined state table;
 * return the next state according the the rules.
 */
gecos_state_t
gecos_scan_state(gecos_state_t instate, char ch)
{
    if (ch == gecos_ignore_c) {
        return (gecos_fsm[instate][0]);
    } else if (ch == gecos_sep_c) {
        return (gecos_fsm[instate][1]);
    } else if (ch == gecos_samename) {
        return (gecos_fsm[instate][2]);
    } else if (isalpha(ch)) {
        return (gecos_fsm[instate][3]);
    } else if (isdigit(ch)) {
        return (gecos_fsm[instate][4]);
    } else if (isspace(ch)) {
        return (gecos_fsm[instate][5]);
    } else if (ch == '.' || ch == '-' || ch == '_') {
        return (gecos_fsm[instate][6]);
    } else if (ispunct(ch)) {
        return (gecos_fsm[instate][7]);
    } else if (ch == '\0') {
        return (gecos_fsm[instate][8]);
    }
    return (gecos_fsm[instate][9]);
}


/*
 * Compare the given argument, which is taken to be a username, with
 * the login name and with strings in the the pw_gecos field.
 */
int
matchcmp(char *gname, char *login, char *given)
{
    char    buffer[100];
    char    *bp, *lp, *gp;

    gecos_state_t kstate = S0;
    gecos_state_t kstate_next = S0;

    if (*gname == '\0' && *given == '\0')
        return (1);

    bp = buffer;
    gp = gname;

    do {
        kstate_next = gecos_scan_state(kstate, *gp);

        switch (kstate_next) {

        case S0:
            gp++;
            break;
        case S1:
            if (bp < buffer + sizeof (buffer)) {
                *bp++ = *gp++;
            }
            break;
        case S2:
            if (kstate == S1 || kstate == S3) {
                *bp++ = ' ';
            }
            gp++;
            break;
        case S3:
            lp = login;
            do {
                *bp++ = *lp++;
            } while (*bp != '\0' && bp < buffer + sizeof (buffer));
            bp--;
            break;
        case S4:
            *bp++ = '\0';
            break;
        default:
            *bp++ = '\0';
            break;
        }
        kstate = kstate_next;

    } while ((bp < buffer + sizeof (buffer)) && kstate != S4);

    gp = strtok(buffer, " ");

    while (gp != NULL) {
        if (namecmp(gp, given) > 0) {
            return (1);
        }
        gp = strtok(NULL, " ");
    }
    return (0);
}

/*
 * Perform the character-by-character comparison.
 * It is intended that "finger foo" should match "foo2", but an argument
 * consisting entirely of digits should not be matched too broadly.
 * Also, we do not want "finger foo123" to match "Mr. Foo" in the gecos.
 */
int
namecmp(char *name1, char *name2)
{
    char c1, c2;
    boolean_t alphaseen = B_FALSE;
    boolean_t digitseen = B_FALSE;

    for (;;) {
        c1 = *name1++;
        if (isalpha(c1))
            alphaseen = B_TRUE;
        if (isdigit(c1))
            digitseen = B_TRUE;
        if (isupper(c1))
            c1 = tolower(c1);

        c2 = *name2++;
        if (isupper(c2))
            c2 = tolower(c2);

        if (c1 != c2)
            break;
        if (c1 == '\0')
            return (1);
    }
    if (!c1) {
        for (name2--; isdigit(*name2); name2++)
            ;
        if (*name2 == '\0' && digitseen) {
            return (1);
        }
    } else if (!c2) {
        for (name1--; isdigit(*name1); name1++)
            ;
        if (*name1 == '\0' && alphaseen) {
            return (1);
        }
    }
    return (0);
}


int
netfinger(char *name)
{
    char *host;
    struct hostent *hp;
    struct sockaddr_in6 sin6;
    struct in6_addr ipv6addr;
    struct in_addr ipv4addr;
    int s;
    FILE *f;
    int c;
    int lastc;
    char abuf[INET6_ADDRSTRLEN];
    int error_num;

    if (name == NULL)
        return (0);
    host = strrchr(name, '@');
    if (host == NULL)
        return (0);
    *host++ = 0;

    if ((hp = getipnodebyname(host, AF_INET6, AI_ALL | AI_ADDRCONFIG |
        AI_V4MAPPED, &error_num)) == NULL) {
        if (error_num == TRY_AGAIN) {
            (void) fprintf(stderr,
                "unknown host: %s (try again later)\n", host);
        } else {
            (void) fprintf(stderr, "unknown host: %s\n", host);
        }
        return (1);
    }

    /*
     * If hp->h_name is a IPv4-mapped IPv6 literal, we'll convert it to
     * IPv4 literal address.
     */
    if ((inet_pton(AF_INET6, hp->h_name, &ipv6addr) > 0) &&
        IN6_IS_ADDR_V4MAPPED(&ipv6addr)) {
        IN6_V4MAPPED_TO_INADDR(&ipv6addr, &ipv4addr);
        (void) printf("[%s] ", inet_ntop(AF_INET, &ipv4addr, abuf,
            sizeof (abuf)));
    } else {
        (void) printf("[%s] ", hp->h_name);
    }
    bzero(&sin6, sizeof (sin6));
    sin6.sin6_family = hp->h_addrtype;
    bcopy(hp->h_addr_list[0], (char *)&sin6.sin6_addr, hp->h_length);
    sin6.sin6_port = htons(IPPORT_FINGER);
    s = socket(sin6.sin6_family, SOCK_STREAM, 0);
    if (s < 0) {
        (void) fflush(stdout);
        perror("socket");
        freehostent(hp);
        return (1);
    }
    while (connect(s, (struct sockaddr *)&sin6, sizeof (sin6)) < 0) {

        if (hp && hp->h_addr_list[1]) {

            hp->h_addr_list++;
            bcopy(hp->h_addr_list[0],
                (caddr_t)&sin6.sin6_addr, hp->h_length);
            (void) close(s);
            s = socket(sin6.sin6_family, SOCK_STREAM, 0);
            if (s < 0) {
                (void) fflush(stdout);
                perror("socket");
                freehostent(hp);
                return (0);
            }
            continue;
        }

        (void) fflush(stdout);
        perror("connect");
        (void) close(s);
        freehostent(hp);
        return (1);
    }
    freehostent(hp);
    hp = NULL;

    (void) printf("\n");
    if (large)
        (void) write(s, "/W ", 3);
    (void) write(s, name, strlen(name));
    (void) write(s, "\r\n", 2);
    f = fdopen(s, "r");

    lastc = '\n';
    while ((c = getc(f)) != EOF) {
        /* map CRLF -> newline */
        if ((lastc == '\r') && (c != '\n'))
            /* print out saved CR */
            (void) putchar('\r');
        lastc = c;
        if (c == '\r')
            continue;
        (void) putchar(c);
    }

    if (lastc != '\n')
        (void) putchar('\n');
    (void) fclose(f);
    return (1);
}

/*
 *  AnyMail - takes a username (string pointer thereto), and
 *  prints on standard output whether there is any unread mail,
 *  and if so, how old it is.   (JCM@Shasta 15 March 80)
 */
void
AnyMail(char *name)
{
    struct stat buf;        /* space for file status buffer */
    char *mbxdir = MAILDIR;     /* string with path preamble */
    char *mbxpath;          /* space for entire pathname */

    char *timestr;

    mbxpath = malloc(strlen(name) + strlen(MAILDIR) + 1);
    if (mbxpath == NULL)
        return;

    (void) strcpy(mbxpath, mbxdir); /* copy preamble into path name */
    (void) strcat(mbxpath, name);   /* concatenate user name to path */

    if (stat(mbxpath, &buf) == -1 || buf.st_size == 0) {
        /* Mailbox is empty or nonexistent */
        (void) printf("No unread mail\n");
    } else {
        if (buf.st_mtime < buf.st_atime) {
            /*
             * No new mail since the last time the user read it.
             */
            (void) printf("Mail last read ");
            (void) printf("%s", ctime(&buf.st_atime));
        } else if (buf.st_mtime > buf.st_atime) {
            /*
             * New mail has definitely arrived since the last time
             * mail was read.  mtime is the time the most recent
             * message arrived; atime is either the time the oldest
             * unread message arrived, or the last time the mail
             * was read.
             */
            (void) printf("New mail received ");
            timestr = ctime(&buf.st_mtime); /* time last modified */
            timestr[24] = '\0'; /* suppress newline (ugh) */
            (void) printf("%s", timestr);
            (void) printf(";\n  unread since ");
            (void) printf("%s", ctime(&buf.st_atime));
        } else {
            /*
             * There is something in mailbox, but we can't really
             * be sure whether it is mail held there by the user
             * or a (single) new message that was placed in a newly
             * recreated mailbox, so punt and call it "unread mail."
             */
            (void) printf("Unread mail since ");
            (void) printf("%s", ctime(&buf.st_mtime));
        }
    }
    free(mbxpath);
}

/*
 * return true iff we've already printed project/plan for this uid;
 * if not, enter this uid into table (so this function has a side-effect.)
 */
#define PPMAX   4096        /* assume no more than 4096 logged-in users */
uid_t   PlanPrinted[PPMAX+1];
int PPIndex = 0;        /* index of next unused table entry */

int
AlreadyPrinted(uid_t uid)
{
    int i = 0;

    while (i++ < PPIndex) {
        if (PlanPrinted[i] == uid)
        return (1);
    }
    if (i < PPMAX) {
        PlanPrinted[i] = uid;
        PPIndex++;
    }
    return (0);
}

#define FIFOREADTIMEOUT (60)    /* read timeout on select */
/* BEGIN CSTYLED */
#define PRINT_CHAR(c)                       \
    (                           \
        ((termpass & TS_HIGH) && ((int)c) > 126)    \
        ||                      \
        (isascii((int)c) &&                 \
             (isprint((int)c) || isspace((int)c))   \
        )                       \
        ||                      \
        ((termpass & TS_LOW) && ((int)c) < 32)      \
    )
/* END CSTYLED */


void
catfile(char *s, mode_t mode, int trunc_at_nl)
{
    if (S_ISFIFO(mode)) {
        int fd;

        fd = open(s, O_RDONLY | O_NONBLOCK);
        if (fd != -1) {
            fd_set readfds, exceptfds;
            struct timeval tv;

            FD_ZERO(&readfds);
            FD_ZERO(&exceptfds);
            FD_SET(fd, &readfds);
            FD_SET(fd, &exceptfds);

            timerclear(&tv);
            tv.tv_sec = FIFOREADTIMEOUT;

            (void) fflush(stdout);
            while (select(fd + 1, &readfds, (fd_set *) 0,
                &exceptfds, &tv) != -1) {
                unsigned char buf[BUFSIZ];
                int nread;

                nread = read(fd, buf, sizeof (buf));
                if (nread > 0) {
                    unsigned char *p;

                    FD_SET(fd, &readfds);
                    FD_SET(fd, &exceptfds);
                    for (p = buf; p < buf + nread; p++) {
                        if (trunc_at_nl && *p == '\n')
                            goto out;
                        if (PRINT_CHAR(*p))
                            (void) putchar((int)*p);
                        else if (isascii(*p))
                            (void) fputs(unctrl(*p),
                                stdout);
                    }
                } else
                    break;
            }
out:
            (void) close(fd);
        }
    } else {
        int c;
        FILE *fp;

        fp = fopen(s, "r");
        if (fp) {
            while ((c = getc(fp)) != EOF) {
                if (trunc_at_nl && c == '\n')
                    break;
                if (PRINT_CHAR(c))
                    (void) putchar((int)c);
                else
                    if (isascii(c))
                        (void) fputs(unctrl(c), stdout);
            }
            (void) fclose(fp);
        }
    }
}


void
initscreening(void)
{
    char *options, *value;

    if (defopen(defaultfile) == 0) {
        char    *cp;
        int flags;

        /*
         * ignore case
         */
        flags = defcntl(DC_GETFLAGS, 0);
        TURNOFF(flags, DC_CASE);
        (void) defcntl(DC_SETFLAGS, flags);

        if (cp = defread(passvar)) {
            options = cp;
            while (*options != '\0')
                switch (getsubopt(&options, termopts, &value)) {
                case TERM_LOW:
                    termpass |= TS_LOW;
                    break;
                case TERM_HIGH:
                    termpass |= TS_HIGH;
                    break;
                }
        }
        (void) defopen(NULL);   /* close default file */
    }
}

int
person_compare(const void *p1, const void *p2)
{
    const struct person *pp1 = *(struct person **)p1;
    const struct person *pp2 = *(struct person **)p2;
    int r;

    /*
     * Sort by username.
     */
    r = strcmp(pp1->name, pp2->name);

    if (r != 0)
        return (r);

    /*
     * If usernames are the same, sort by idle time.
     */
    r = pp1->idletime - pp2->idletime;

    return (r);
}

void
sort_by_username()
{
    struct person **sortable, *loop;
    size_t i;

    sortable = malloc(sizeof (sortable[0]) * nperson);

    if (sortable == NULL)
        return;

    for (i = 0, loop = person1; i < nperson; i++) {
        struct person *next = loop->link;

        sortable[i] = loop;
        loop->link = NULL;

        loop = next;
    }

    qsort(sortable, nperson, sizeof (sortable[0]), person_compare);

    for (i = 1; i < nperson; i++)
        sortable[i-1]->link = sortable[i];
    person1 = sortable[0];

    free(sortable);
}