From 5fd83771641d15c418f747bd343ba6738d3875f7 Mon Sep 17 00:00:00 2001 From: Cameron Katri Date: Sun, 9 May 2021 14:20:58 -0400 Subject: Import macOS userland adv_cmds-176 basic_cmds-55 bootstrap_cmds-116.100.1 developer_cmds-66 diskdev_cmds-667.40.1 doc_cmds-53.60.1 file_cmds-321.40.3 mail_cmds-35 misc_cmds-34 network_cmds-606.40.1 patch_cmds-17 remote_cmds-63 shell_cmds-216.60.1 system_cmds-880.60.2 text_cmds-106 --- text_cmds/tail/tail.c | 349 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 349 insertions(+) create mode 100644 text_cmds/tail/tail.c (limited to 'text_cmds/tail/tail.c') diff --git a/text_cmds/tail/tail.c b/text_cmds/tail/tail.c new file mode 100644 index 0000000..57129ef --- /dev/null +++ b/text_cmds/tail/tail.c @@ -0,0 +1,349 @@ +/*- + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. 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 + +__FBSDID("$FreeBSD$"); + +#ifndef lint +static const char copyright[] = +"@(#) Copyright (c) 1991, 1993\n\ + The Regents of the University of California. All rights reserved.\n"; +#endif + +#ifndef lint +static const char sccsid[] = "@(#)tail.c 8.1 (Berkeley) 6/6/93"; +#endif + +#include +#include + +#include +#include +#include +#include +#include +#include + +#include "extern.h" + +int Fflag, fflag, qflag, rflag, rval, no_files; +const char *fname; + +file_info_t *files; + +static void obsolete(char **); +static void usage(void); + +int +main(int argc, char *argv[]) +{ + struct stat sb; + FILE *fp; + off_t off; + enum STYLE style; + int i, ch, first; + file_info_t *file; + char *p; + + /* + * 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) { \ + if (style) \ + usage(); \ + off = strtoll(optarg, &p, 10) * (units); \ + if (*p) \ + errx(1, "illegal offset -- %s", optarg); \ + switch(optarg[0]) { \ + case '+': \ + if (off) \ + off -= (units); \ + style = (forward); \ + break; \ + case '-': \ + off = -off; \ + /* FALLTHROUGH */ \ + default: \ + style = (backward); \ + break; \ + } \ +} + + obsolete(argv); + style = NOTSET; + while ((ch = getopt(argc, argv, "Fb:c:fn:qr")) != -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; + break; + case 'r': + rflag = 1; + break; + case '?': + default: + usage(); + } + argc -= optind; + argv += optind; + + no_files = argc ? argc : 1; + + /* + * 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 (fflag && !argc) { + /* + * 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 (fflag) { + files = (struct file_info *) malloc(no_files * sizeof(struct file_info)); + if (! files) + err(1, "Couldn't malloc space for file descriptors."); + + for (file = files; (fname = argc ? *argv++ : "stdin"); file++) { + file->file_name = malloc(strlen(fname)+1); + if (! file->file_name) + errx(1, "Couldn't malloc space for file name."); + strncpy(file->file_name, fname, strlen(fname)+1); + file->fp = argc ? fopen(file->file_name, "r") : stdin; + if (file->fp == NULL || + fstat(fileno(file->fp), &file->st)) { + file->fp = NULL; + ierr(); + continue; + } + if (!argc) + break; + } + follow(files, style, off); + for (i = 0, file = files; i < no_files; i++, file++) { + free(file->file_name); + } + free(files); + } else if (*argv) { + for (first = 1; (fname = *argv++);) { + if ((fp = fopen(fname, "r")) == NULL || + fstat(fileno(fp), &sb)) { + ierr(); + continue; + } + if (argc > 1 && !qflag) { + (void)printf("%s==> %s <==\n", + first ? "" : "\n", fname); + first = 0; + (void)fflush(stdout); + } + +#ifdef __APPLE__ + /* 3849683: don't read a directory */ + if (S_IFDIR == (sb.st_mode & S_IFMT)) + continue; +#endif + + if (rflag) + reverse(fp, style, off, &sb); + else + forward(fp, style, off, &sb); + } + } else { + fname = "stdin"; + + if (fstat(fileno(stdin), &sb)) { + ierr(); + exit(1); + } + + if (rflag) + reverse(stdin, style, off, &sb); + else + forward(stdin, style, off, &sb); + } + 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, "malloc"); + *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); +} -- cgit v1.2.3-56-ge451