/*      $OpenBSD: logger.c,v 1.19 2022/12/04 23:50:48 cheloha Exp $     */
/*      $NetBSD: logger.c,v 1.4 1994/12/22 06:27:00 jtc Exp $   */

/*
 * Copyright (c) 1983, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, 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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <errno.h>
#include <unistd.h>
#include <limits.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <err.h>

#define SYSLOG_NAMES
#include <syslog.h>

int     decode(char *, CODE *);
int     pencode(char *);
void    usage(void);

/*
 * logger -- read and log utility
 *
 *      Reads from an input and arranges to write the result on the system
 *      log.
 */
int
main(int argc, char *argv[])
{
        int ch, logflags, pri;
        char *tag, buf[1024];

        tag = NULL;
        pri = LOG_NOTICE;
        logflags = 0;
        while ((ch = getopt(argc, argv, "cf:ip:st:")) != -1)
                switch(ch) {
                case 'c':               /* log to console */
                        logflags |= LOG_CONS;
                        break;
                case 'f':               /* file to log */
                        if (freopen(optarg, "r", stdin) == NULL) {
                                (void)fprintf(stderr, "logger: %s: %s.\n",
                                    optarg, strerror(errno));
                                exit(1);
                        }
                        break;
                case 'i':               /* log process id also */
                        logflags |= LOG_PID;
                        break;
                case 'p':               /* priority */
                        pri = pencode(optarg);
                        break;
                case 's':               /* log to standard error */
                        logflags |= LOG_PERROR;
                        break;
                case 't':               /* tag */
                        tag = optarg;
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        /* setup for logging */
        openlog(tag ? tag : getlogin(), logflags, 0);
        (void) fclose(stdout);

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        /* log input line if appropriate */
        if (argc > 0) {
                char *p, *endp;
                size_t len;

                for (p = buf, endp = buf + sizeof(buf) - 2; *argv;) {
                        len = strlen(*argv);
                        if (p + len > endp && p > buf) {
                                syslog(pri, "%s", buf);
                                p = buf;
                        }
                        if (len > sizeof(buf) - 1)
                                syslog(pri, "%s", *argv++);
                        else {
                                if (p != buf)
                                        *p++ = ' ';
                                bcopy(*argv++, p, len);
                                *(p += len) = '\0';
                        }
                }
                if (p != buf)
                        syslog(pri, "%s", buf);
        } else
                while (fgets(buf, sizeof(buf), stdin) != NULL)
                        syslog(pri, "%s", buf);
        exit(0);
}

/*
 *  Decode a symbolic name to a numeric value
 */
int
pencode(char *s)
{
        char *save;
        int fac, lev;

        for (save = s; *s && *s != '.'; ++s);
        if (*s) {
                *s = '\0';
                fac = decode(save, facilitynames);
                if (fac < 0) {
                        (void)fprintf(stderr,
                            "logger: unknown facility name: %s.\n", save);
                        exit(1);
                }
                *s++ = '.';
        }
        else {
                fac = 0;
                s = save;
        }
        lev = decode(s, prioritynames);
        if (lev < 0) {
                (void)fprintf(stderr,
                    "logger: unknown priority name: %s.\n", save);
                exit(1);
        }
        return ((lev & LOG_PRIMASK) | (fac & LOG_FACMASK));
}

int
decode(char *name, CODE *codetab)
{
        CODE *c;

        if (isdigit((unsigned char)*name)) {
                const char *errstr;
                int n = strtonum(name, 0, INT_MAX, &errstr);
                if (!errstr)
                        return (n);
        }

        for (c = codetab; c->c_name; c++)
                if (!strcasecmp(name, c->c_name))
                        return (c->c_val);

        return (-1);
}

void
usage(void)
{
        (void)fprintf(stderr,
            "usage: logger [-cis] [-f file] [-p pri] [-t tag] [message ...]\n");
        exit(1);
}