diff options
Diffstat (limited to 'usr.bin/tail/tail.c')
| -rw-r--r-- | usr.bin/tail/tail.c | 370 |
1 files changed, 370 insertions, 0 deletions
diff --git a/usr.bin/tail/tail.c b/usr.bin/tail/tail.c new file mode 100644 index 000000000000..a92eee3881b4 --- /dev/null +++ b/usr.bin/tail/tail.c @@ -0,0 +1,370 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * Copyright (c) 1991, 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Edward Sze-Tyan Wang. + * + * 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 <sys/capsicum.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <capsicum_helpers.h> +#include <err.h> +#include <errno.h> +#include <getopt.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> + +#include <libutil.h> + +#include <libcasper.h> +#include <casper/cap_fileargs.h> + +#include "extern.h" + +int Fflag, fflag, qflag, rflag, rval, no_files, vflag; +fileargs_t *fa; + +static void obsolete(char **); +static void usage(void) __dead2; + +static const struct option long_opts[] = +{ + {"blocks", required_argument, NULL, 'b'}, + {"bytes", required_argument, NULL, 'c'}, + {"lines", required_argument, NULL, 'n'}, + {"quiet", no_argument, NULL, 'q'}, + {"silent", no_argument, NULL, 'q'}, + {"verbose", no_argument, NULL, 'v'}, + {NULL, no_argument, NULL, 0} +}; + +int +main(int argc, char *argv[]) +{ + struct stat sb; + const char *fn; + FILE *fp; + off_t off; + enum STYLE style; + int ch, first; + file_info_t file, *filep, *files; + cap_rights_t rights; + + /* + * Tail's options are weird. First, -n10 is the same as -n-10, not + * -n+10. Second, the number options are 1 based and not offsets, + * so -n+1 is the first line, and -c-1 is the last byte. Third, the + * number options for the -r option specify the number of things that + * get displayed, not the starting point in the file. The one major + * incompatibility in this version as compared to historical versions + * is that the 'r' option couldn't be modified by the -lbc options, + * i.e. it was always done in lines. This version treats -rc as a + * number of characters in reverse order. Finally, the default for + * -r is the entire file, not 10 lines. + */ +#define ARG(units, forward, backward) { \ + int64_t num; \ + if (style) \ + usage(); \ + if (expand_number(optarg, &num)) \ + err(1, "illegal offset -- %s", optarg); \ + if (num > INT64_MAX / units || num < INT64_MIN / units) \ + errx(1, "illegal offset -- %s", optarg); \ + off = num * units; \ + switch (optarg[0]) { \ + case '+': \ + if (off != 0) \ + off -= (units); \ + style = (forward); \ + break; \ + case '-': \ + off = -off; \ + /* FALLTHROUGH */ \ + default: \ + style = (backward); \ + break; \ + } \ +} + + obsolete(argv); + style = NOTSET; + off = 0; + while ((ch = getopt_long(argc, argv, "+Fb:c:fn:qrv", long_opts, NULL)) != + -1) + switch (ch) { + case 'F': /* -F is superset of (and implies) -f */ + Fflag = fflag = 1; + break; + case 'b': + ARG(512, FBYTES, RBYTES); + break; + case 'c': + ARG(1, FBYTES, RBYTES); + break; + case 'f': + fflag = 1; + break; + case 'n': + ARG(1, FLINES, RLINES); + break; + case 'q': + qflag = 1; + vflag = 0; + break; + case 'r': + rflag = 1; + break; + case 'v': + vflag = 1; + qflag = 0; + break; + case '?': + default: + usage(); + } + argc -= optind; + argv += optind; + + no_files = argc ? argc : 1; + + cap_rights_init(&rights, CAP_FSTAT, CAP_FSTATFS, CAP_FCNTL, + CAP_MMAP_R); + if (fflag) + cap_rights_set(&rights, CAP_EVENT); + if (caph_rights_limit(STDIN_FILENO, &rights) < 0 || + caph_limit_stderr() < 0 || caph_limit_stdout() < 0) + err(1, "unable to limit stdio rights"); + + fa = fileargs_init(argc, argv, O_RDONLY, 0, &rights, FA_OPEN); + if (fa == NULL) + err(1, "unable to init casper"); + + caph_cache_catpages(); + if (caph_enter_casper() < 0) + err(1, "unable to enter capability mode"); + + /* + * If displaying in reverse, don't permit follow option, and convert + * style values. + */ + if (rflag) { + if (fflag) + usage(); + if (style == FBYTES) + style = RBYTES; + else if (style == FLINES) + style = RLINES; + } + + /* + * If style not specified, the default is the whole file for -r, and + * the last 10 lines if not -r. + */ + if (style == NOTSET) { + if (rflag) { + off = 0; + style = REVERSE; + } else { + off = 10; + style = RLINES; + } + } + + if (*argv && fflag) { + files = malloc(no_files * sizeof(struct file_info)); + if (files == NULL) + err(1, "failed to allocate memory for file descriptors"); + + for (filep = files; (fn = *argv++); filep++) { + filep->file_name = fn; + filep->fp = fileargs_fopen(fa, filep->file_name, "r"); + if (filep->fp == NULL || + fstat(fileno(filep->fp), &filep->st)) { + if (filep->fp != NULL) { + fclose(filep->fp); + filep->fp = NULL; + } + if (!Fflag || errno != ENOENT) + ierr(filep->file_name); + } + } + follow(files, style, off); + free(files); + } else if (*argv) { + for (first = 1; (fn = *argv++);) { + if ((fp = fileargs_fopen(fa, fn, "r")) == NULL || + fstat(fileno(fp), &sb)) { + ierr(fn); + continue; + } + if (vflag || (qflag == 0 && argc > 1)) { + printfn(fn, !first); + first = 0; + } + + if (rflag) + reverse(fp, fn, style, off, &sb); + else + forward(fp, fn, style, off, &sb); + } + } else { + fn = "stdin"; + + if (fstat(fileno(stdin), &sb)) { + ierr(fn); + exit(1); + } + + /* + * Determine if input is a pipe. 4.4BSD will set the SOCKET + * bit in the st_mode field for pipes. Fix this then. + */ + if (lseek(fileno(stdin), (off_t)0, SEEK_CUR) == -1 && + errno == ESPIPE) { + errno = 0; + fflag = 0; /* POSIX.2 requires this. */ + } + + if (rflag) { + reverse(stdin, fn, style, off, &sb); + } else if (fflag) { + file.file_name = fn; + file.fp = stdin; + file.st = sb; + follow(&file, style, off); + } else { + forward(stdin, fn, style, off, &sb); + } + } + fileargs_free(fa); + exit(rval); +} + +/* + * Convert the obsolete argument form into something that getopt can handle. + * This means that anything of the form [+-][0-9][0-9]*[lbc][Ffr] that isn't + * the option argument for a -b, -c or -n option gets converted. + */ +static void +obsolete(char *argv[]) +{ + char *ap, *p, *t; + size_t len; + char *start; + + while ((ap = *++argv)) { + /* Return if "--" or not an option of any form. */ + if (ap[0] != '-') { + if (ap[0] != '+') + return; + } else if (ap[1] == '-') + return; + + switch(*++ap) { + /* Old-style option. */ + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + + /* Malloc space for dash, new option and argument. */ + len = strlen(*argv); + if ((start = p = malloc(len + 3)) == NULL) + err(1, "failed to allocate memory"); + *p++ = '-'; + + /* + * Go to the end of the option argument. Save off any + * trailing options (-3lf) and translate any trailing + * output style characters. + */ + t = *argv + len - 1; + if (*t == 'F' || *t == 'f' || *t == 'r') { + *p++ = *t; + *t-- = '\0'; + } + switch(*t) { + case 'b': + *p++ = 'b'; + *t = '\0'; + break; + case 'c': + *p++ = 'c'; + *t = '\0'; + break; + case 'l': + *t = '\0'; + /* FALLTHROUGH */ + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': + *p++ = 'n'; + break; + default: + errx(1, "illegal option -- %s", *argv); + } + *p++ = *argv[0]; + (void)strcpy(p, ap); + *argv = start; + continue; + + /* + * Options w/ arguments, skip the argument and continue + * with the next option. + */ + case 'b': + case 'c': + case 'n': + if (!ap[1]) + ++argv; + /* FALLTHROUGH */ + /* Options w/o arguments, continue with the next option. */ + case 'F': + case 'f': + case 'r': + continue; + + /* Illegal option, return and let getopt handle it. */ + default: + return; + } + } +} + +static void +usage(void) +{ + (void)fprintf(stderr, + "usage: tail [-F | -f | -r] [-q] [-b # | -c # | -n #]" + " [file ...]\n"); + exit(1); +} |