diff options
Diffstat (limited to 'coreutils')
| -rw-r--r-- | coreutils/tail.c | 1364 |
1 files changed, 245 insertions, 1119 deletions
diff --git a/coreutils/tail.c b/coreutils/tail.c index 2746af8..4a1aa84 100644 --- a/coreutils/tail.c +++ b/coreutils/tail.c @@ -1,15 +1,4 @@ /* vi: set sw=4 ts=4: */ -#include "internal.h" - -/* This file contains _two_ implementations of tail. One is - * a bit more full featured, but costs 6k. The other (i.e. the - * SIMPLE_TAIL one) is less capable, but is good enough for about - * 99% of the things folks want to use tail for, and only costs 2k. - */ - - -#ifdef BB_FEATURE_SIMPLE_TAIL - /* tail -- output the last part of file(s) Copyright (C) 89, 90, 91, 95, 1996 Free Software Foundation, Inc. @@ -32,1163 +21,300 @@ tail -f for multiple files by Ian Lance Taylor <ian@airs.com>. Rewrote the option parser, removed locales support, - and generally busyboxed, Erik Andersen <andersen@lineo.com> + and generally busyboxed, Erik Andersen <andersen@lineo.com> Removed superfluous options and associated code ("-c", "-n", "-q"). Removed "tail -f" support for multiple files. Both changes by Friedrich Vedder <fwv@myrtle.lahn.de>. - */ - + Compleate Rewrite to correctly support "-NUM", "+NUM", and "-s" by + E.Allen Soard (esp@espsw.net). -#include <stdio.h> -#include <stdarg.h> + */ #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> -#include <ctype.h> -#define BB_DECLARE_EXTERN -#define bb_need_help -#include "messages.c" +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <getopt.h> +#include "internal.h" +#define STDIN "standard input" +#define LINES 0 +#define BYTES 1 -#define XWRITE(fd, buffer, n_bytes) \ - do { \ - if (n_bytes > 0 && fwrite ((buffer), 1, (n_bytes), stdout) == 0) \ - errorMsg("write error"); \ - } while (0) +static int n_files = 0; +static char **files = NULL; -/* Number of items to tail. */ -#define DEFAULT_N_LINES 10 +static char follow=0; -/* Size of atomic reads. */ -#ifndef BUFSIZ -#define BUFSIZ (512 * 8) +#ifdef BB_FEATURE_SIMPLE_TAIL +static const char unit_type=LINES; +static const char sleep_int=1; +#else +static char unit_type=LINES; +static int sleep_int=1; +static char verbose = 0; #endif -/* If nonzero, read from the end of one file until killed. */ -static int forever; - -/* If nonzero, print filename headers. */ -static int print_headers; +//static off_t units=-11; +static off_t units=0; -static void write_header(const char *filename) +int tail_stream(int file_id) { - static int first_file = 1; - - printf("%s==> %s <==\n", (first_file ? "" : "\n"), filename); - first_file = 0; -} - -/* Print the last N_LINES lines from the end of file FD. - Go backward through the file, reading `BUFSIZ' bytes at a time (except - probably the first), until we hit the start of the file or have - read NUMBER newlines. - POS starts out as the length of the file (the offset of the last - byte of the file + 1). - Return 0 if successful, 1 if an error occurred. */ - -static int -file_lines(int fd, long int n_lines, off_t pos) -{ - char buffer[BUFSIZ]; - int bytes_read; - int i; /* Index into `buffer' for scanning. */ - - if (n_lines == 0) - return 0; - - /* Set `bytes_read' to the size of the last, probably partial, buffer; - 0 < `bytes_read' <= `BUFSIZ'. */ - bytes_read = pos % BUFSIZ; - if (bytes_read == 0) - bytes_read = BUFSIZ; - /* Make `pos' a multiple of `BUFSIZ' (0 if the file is short), so that all - reads will be on block boundaries, which might increase efficiency. */ - pos -= bytes_read; - lseek(fd, pos, SEEK_SET); - bytes_read = fullRead(fd, buffer, bytes_read); - if (bytes_read == -1) - errorMsg("read error"); - - /* Count the incomplete line on files that don't end with a newline. */ - if (bytes_read && buffer[bytes_read - 1] != '\n') - --n_lines; - - do { - /* Scan backward, counting the newlines in this bufferfull. */ - for (i = bytes_read - 1; i >= 0; i--) { - /* Have we counted the requested number of newlines yet? */ - if (buffer[i] == '\n' && n_lines-- == 0) { - /* If this newline wasn't the last character in the buffer, - print the text after it. */ - if (i != bytes_read - 1) - XWRITE(STDOUT_FILENO, &buffer[i + 1], - bytes_read - (i + 1)); - return 0; + int fd; + ssize_t bytes_read=0; + ssize_t bs=BUFSIZ; + ssize_t startpoint=bs; + ssize_t endpoint=0; + ssize_t count=0; + ssize_t filesize=0; + ssize_t filelocation=0; + char direction=1; + char * buffer; + char pipe; + + + if (!strcmp(files[file_id], STDIN)) + fd = 0; + else + fd = open(files[file_id], O_RDONLY); + if (fd == -1) + fatalError("Unable to open file %s.\n", files[file_id]); + + buffer=malloc(bs); + + filesize=lseek(fd, -1, SEEK_END)+1; + pipe=(filesize<=0); + + if(units>=0) + lseek(fd,0,SEEK_SET); + else { + direction=-1; + count=1; + } + while(units != 0) { + if (pipe) { + char * line; + ssize_t f_size=0; + + bs=BUFSIZ; + line=malloc(bs); + while(1) { + bytes_read=read(fd,line,bs); + if(bytes_read<=0) + break; + buffer=realloc(buffer,f_size+bytes_read); + memcpy(&buffer[f_size],line,bytes_read); + filelocation=f_size+=bytes_read; } - } - /* Not enough newlines in that bufferfull. */ - if (pos == 0) { - /* Not enough lines in the file; print the entire file. */ - lseek(fd, (off_t) 0, SEEK_SET); - return 0; - } - pos -= BUFSIZ; - lseek(fd, pos, SEEK_SET); - } - while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0); - if (bytes_read == -1) - errorMsg("read error"); - - return 0; -} - -/* Print the last N_LINES lines from the end of the standard input, - open for reading as pipe FD. - Buffer the text as a linked list of LBUFFERs, adding them as needed. - Return 0 if successful, 1 if an error occured. */ - -static int pipe_lines(int fd, long int n_lines) -{ - struct linebuffer { - int nbytes, nlines; - char buffer[BUFSIZ]; - struct linebuffer *next; - }; - typedef struct linebuffer LBUFFER; - LBUFFER *first, *last, *tmp; - int i; /* Index into buffers. */ - int total_lines = 0; /* Total number of newlines in all buffers. */ - int errors = 0; - - first = last = (LBUFFER *) xmalloc(sizeof(LBUFFER)); - first->nbytes = first->nlines = 0; - first->next = NULL; - tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER)); - - /* Input is always read into a fresh buffer. */ - while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) { - tmp->nlines = 0; - tmp->next = NULL; - - /* Count the number of newlines just read. */ - for (i = 0; i < tmp->nbytes; i++) - if (tmp->buffer[i] == '\n') - ++tmp->nlines; - total_lines += tmp->nlines; - - /* If there is enough room in the last buffer read, just append the new - one to it. This is because when reading from a pipe, `nbytes' can - often be very small. */ - if (tmp->nbytes + last->nbytes < BUFSIZ) { - memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes); - last->nbytes += tmp->nbytes; - last->nlines += tmp->nlines; + bs=f_size; + if(direction<0) + bs--; + if (line) + free(line); } else { - /* If there's not enough room, link the new buffer onto the end of - the list, then either free up the oldest buffer for the next - read if that would leave enough lines, or else malloc a new one. - Some compaction mechanism is possible but probably not - worthwhile. */ - last = last->next = tmp; - if (total_lines - first->nlines > n_lines) { - tmp = first; - total_lines -= first->nlines; - first = first->next; - } else - tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER)); - } - } - if (tmp->nbytes == -1) - errorMsg("read error"); - - free((char *) tmp); - - /* This prevents a core dump when the pipe contains no newlines. */ - if (n_lines == 0) - goto free_lbuffers; - - /* Count the incomplete line on files that don't end with a newline. */ - if (last->buffer[last->nbytes - 1] != '\n') { - ++last->nlines; - ++total_lines; - } - - /* Run through the list, printing lines. First, skip over unneeded - buffers. */ - for (tmp = first; total_lines - tmp->nlines > n_lines; tmp = tmp->next) - total_lines -= tmp->nlines; - - /* Find the correct beginning, then print the rest of the file. */ - if (total_lines > n_lines) { - char *cp; - - /* Skip `total_lines' - `n_lines' newlines. We made sure that - `total_lines' - `n_lines' <= `tmp->nlines'. */ - cp = tmp->buffer; - for (i = total_lines - n_lines; i; --i) - while (*cp++ != '\n') - /* Do nothing. */ ; - i = cp - tmp->buffer; - } else - i = 0; - XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i); - - for (tmp = tmp->next; tmp; tmp = tmp->next) - XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes); - - free_lbuffers: - while (first) { - tmp = first->next; - free((char *) first); - first = tmp; - } - return errors; -} - -/* Display file FILENAME from the current position in FD to the end. - If `forever' is nonzero, keep reading from the end of the file - until killed. Return the number of bytes read from the file. */ - -static long dump_remainder(int fd) -{ - char buffer[BUFSIZ]; - int bytes_read; - long total; - - total = 0; - output: - while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) { - XWRITE(STDOUT_FILENO, buffer, bytes_read); - total += bytes_read; - } - if (bytes_read == -1) - errorMsg("read error"); - if (forever) { - fflush(stdout); - sleep(1); - goto output; - } - - return total; -} - -/* Output the last N_LINES lines of file FILENAME open for reading in FD. - Return 0 if successful, 1 if an error occurred. */ - -static int tail_lines(const char *filename, int fd, long int n_lines) -{ - struct stat stats; - off_t length; - - if (print_headers) - write_header(filename); - - if (fstat(fd, &stats)) - errorMsg("fstat error"); - - /* Use file_lines only if FD refers to a regular file with - its file pointer positioned at beginning of file. */ - /* FIXME: adding the lseek conjunct is a kludge. - Once there's a reasonable test suite, fix the true culprit: - file_lines. file_lines shouldn't presume that the input - file pointer is initially positioned to beginning of file. */ - if (S_ISREG(stats.st_mode) - && lseek(fd, (off_t) 0, SEEK_CUR) == (off_t) 0) { - length = lseek(fd, (off_t) 0, SEEK_END); - if (length != 0 && file_lines(fd, n_lines, length)) - return 1; - dump_remainder(fd); - } else - return pipe_lines(fd, n_lines); - - return 0; -} - -/* Display the last N_UNITS lines of file FILENAME. - "-" for FILENAME means the standard input. - Return 0 if successful, 1 if an error occurred. */ - -static int tail_file(const char *filename, off_t n_units) -{ - int fd, errors; - - if (!strcmp(filename, "-")) { - filename = "standard input"; - errors = tail_lines(filename, 0, (long) n_units); - } else { - /* Not standard input. */ - fd = open(filename, O_RDONLY); - if (fd == -1) - perror(filename); - - errors = tail_lines(filename, fd, (long) n_units); - close(fd); - } - - return errors; -} - -extern int tail_main(int argc, char **argv) -{ - int exit_status = 0; - int n_units = DEFAULT_N_LINES; - int n_tmp, i; - char opt; - - forever = print_headers = 0; - - /* parse argv[] */ - for (i = 1; i < argc; i++) { - if (argv[i][0] == '-') { - opt = argv[i][1]; - switch (opt) { - case 'f': - forever = 1; - break; - case 'n': - n_tmp = 0; - if (++i < argc) - n_tmp = atoi(argv[i]); - if (n_tmp < 1) - usage(tail_usage); - n_units = n_tmp; - break; - case '-': - case 'h': - usage(tail_usage); - default: - if ((n_units = atoi(&argv[i][1])) < 1) { - errorMsg("invalid option -- %c\n", opt); - usage(tail_usage); - } + filelocation = lseek(fd, 0, SEEK_CUR); + if(direction<0) { + if(filelocation<bs) + bs=filelocation; + filelocation = lseek(fd, -bs, SEEK_CUR); } - } else { - break; + bytes_read = read(fd, buffer, bs); + if (bytes_read <= 0) + break; + bs=bytes_read; } - } - - if (i + 1 < argc) { - if (forever) { - errorMsg("option -f is invalid with multiple files\n"); - usage(tail_usage); + startpoint=bs; + if(direction>0) { + endpoint=startpoint; + startpoint=0; } - print_headers = 1; - } - - if (i >= argc) { - exit_status |= tail_file("-", n_units); - } else { - for (; i < argc; i++) - exit_status |= tail_file(argv[i], n_units); - } - - return(exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE); -} - - -#else -// Here follows the code for the full featured tail code - - -/* tail -- output the last part of file(s) - Copyright (C) 89, 90, 91, 95, 1996 Free Software Foundation, Inc. - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; either version 2, or (at your option) - any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - - Original version by Paul Rubin <phr@ocf.berkeley.edu>. - Extensions by David MacKenzie <djm@gnu.ai.mit.edu>. - tail -f for multiple files by Ian Lance Taylor <ian@airs.com>. - - Rewrote the option parser, removed locales support, - and generally busyboxed, Erik Andersen <andersen@lineo.com> - - */ - -#include "internal.h" - -#include <stdio.h> -#include <stdarg.h> -#include <assert.h> -#include <errno.h> -#include <sys/types.h> -#include <sys/types.h> -#include <sys/stat.h> -#include <fcntl.h> -#include <ctype.h> - - - -/* Disable assertions. Some systems have broken assert macros. */ -#define NDEBUG 1 - - -static void detailed_error(int i, int errnum, char *fmt, ...) - __attribute__ ((format (printf, 3, 4))); -static void detailed_error(int i, int errnum, char *fmt, ...) -{ - va_list arguments; - - va_start(arguments, fmt); - vfprintf(stderr, fmt, arguments); - fprintf(stderr, "\n%s\n", strerror(errnum)); - va_end(arguments); - exit(i); -} - - -#define XWRITE(fd, buffer, n_bytes) \ - do \ - { \ - assert ((fd) == 1); \ - assert ((n_bytes) >= 0); \ - if (n_bytes > 0 && fwrite ((buffer), 1, (n_bytes), stdout) == 0) \ - detailed_error (EXIT_FAILURE, errno, "write error"); \ - } \ - while (0) - -/* Number of items to tail. */ -#define DEFAULT_N_LINES 10 - -/* Size of atomic reads. */ -#ifndef BUFSIZ -#define BUFSIZ (512 * 8) + for(;startpoint!=endpoint;startpoint+=direction) { +#ifndef BB_FEATURE_SIMPLE_TAIL + if(unit_type==BYTES) + count++; + else #endif - -/* If nonzero, interpret the numeric argument as the number of lines. - Otherwise, interpret it as the number of bytes. */ -static int count_lines; - -/* If nonzero, read from the end of one file until killed. */ -static int forever; - -/* If nonzero, read from the end of multiple files until killed. */ -static int forever_multiple; - -/* Array of file descriptors if forever_multiple is 1. */ -static int *file_descs; - -/* Array of file sizes if forever_multiple is 1. */ -static off_t *file_sizes; - -/* If nonzero, count from start of file instead of end. */ -static int from_start; - -/* If nonzero, print filename headers. */ -static int print_headers; - -/* When to print the filename banners. */ -enum header_mode { - multiple_files, always, never -}; - -/* The name this program was run with. */ -char *program_name; - -/* Nonzero if we have ever read standard input. */ -static int have_read_stdin; - -static void write_header(const char *filename, const char *comment) -{ - static int first_file = 1; - - printf("%s==> %s%s%s <==\n", (first_file ? "" : "\n"), filename, - (comment ? ": " : ""), (comment ? comment : "")); - first_file = 0; -} - -/* Print the last N_LINES lines from the end of file FD. - Go backward through the file, reading `BUFSIZ' bytes at a time (except - probably the first), until we hit the start of the file or have - read NUMBER newlines. - POS starts out as the length of the file (the offset of the last - byte of the file + 1). - Return 0 if successful, 1 if an error occurred. */ - -static int -file_lines(const char *filename, int fd, long int n_lines, off_t pos) -{ - char buffer[BUFSIZ]; - int bytes_read; - int i; /* Index into `buffer' for scanning. */ - - if (n_lines == 0) - return 0; - - /* Set `bytes_read' to the size of the last, probably partial, buffer; - 0 < `bytes_read' <= `BUFSIZ'. */ - bytes_read = pos % BUFSIZ; - if (bytes_read == 0) - bytes_read = BUFSIZ; - /* Make `pos' a multiple of `BUFSIZ' (0 if the file is short), so that all - reads will be on block boundaries, which might increase efficiency. */ - pos -= bytes_read; - lseek(fd, pos, SEEK_SET); - bytes_read = fullRead(fd, buffer, bytes_read); - if (bytes_read == -1) { - detailed_error(0, errno, "%s", filename); - return 1; - } - - /* Count the incomplete line on files that don't end with a newline. */ - if (bytes_read && buffer[bytes_read - 1] != '\n') - --n_lines; - - do { - /* Scan backward, counting the newlines in this bufferfull. */ - for (i = bytes_read - 1; i >= 0; i--) { - /* Have we counted the requested number of newlines yet? */ - if (buffer[i] == '\n' && n_lines-- == 0) { - /* If this newline wasn't the last character in the buffer, - print the text after it. */ - if (i != bytes_read - 1) - XWRITE(STDOUT_FILENO, &buffer[i + 1], - bytes_read - (i + 1)); - return 0; - } - } - /* Not enough newlines in that bufferfull. */ - if (pos == 0) { - /* Not enough lines in the file; print the entire file. */ - lseek(fd, (off_t) 0, SEEK_SET); - return 0; + if(buffer[startpoint-1]=='\n') + count++; + if (!pipe) + filelocation=lseek(fd,0,SEEK_CUR); + if(count==abs(units)) + break; } - pos -= BUFSIZ; - lseek(fd, pos, SEEK_SET); - } - while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0); - if (bytes_read == -1) { - detailed_error(0, errno, "%s", filename); - return 1; - } - return 0; -} - -/* Print the last N_LINES lines from the end of the standard input, - open for reading as pipe FD. - Buffer the text as a linked list of LBUFFERs, adding them as needed. - Return 0 if successful, 1 if an error occured. */ - -static int pipe_lines(const char *filename, int fd, long int n_lines) -{ - struct linebuffer { - int nbytes, nlines; - char buffer[BUFSIZ]; - struct linebuffer *next; - }; - typedef struct linebuffer LBUFFER; - LBUFFER *first, *last, *tmp; - int i; /* Index into buffers. */ - int total_lines = 0; /* Total number of newlines in all buffers. */ - int errors = 0; - - first = last = (LBUFFER *) xmalloc(sizeof(LBUFFER)); - first->nbytes = first->nlines = 0; - first->next = NULL; - tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER)); - - /* Input is always read into a fresh buffer. */ - while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) { - tmp->nlines = 0; - tmp->next = NULL; - - /* Count the number of newlines just read. */ - for (i = 0; i < tmp->nbytes; i++) - if (tmp->buffer[i] == '\n') - ++tmp->nlines; - total_lines += tmp->nlines; - - /* If there is enough room in the last buffer read, just append the new - one to it. This is because when reading from a pipe, `nbytes' can - often be very small. */ - if (tmp->nbytes + last->nbytes < BUFSIZ) { - memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes); - last->nbytes += tmp->nbytes; - last->nlines += tmp->nlines; - } else { - /* If there's not enough room, link the new buffer onto the end of - the list, then either free up the oldest buffer for the next - read if that would leave enough lines, or else malloc a new one. - Some compaction mechanism is possible but probably not - worthwhile. */ - last = last->next = tmp; - if (total_lines - first->nlines > n_lines) { - tmp = first; - total_lines -= first->nlines; - first = first->next; - } else - tmp = (LBUFFER *) xmalloc(sizeof(LBUFFER)); + if((count==abs(units)) | pipe) + break; + if(direction<0){ + filelocation = lseek(fd, -bytes_read, SEEK_CUR); + if(filelocation==0) + break; } } - if (tmp->nbytes == -1) { - detailed_error(0, errno, "%s", filename); - errors = 1; - free((char *) tmp); - goto free_lbuffers; - } - - free((char *) tmp); - - /* This prevents a core dump when the pipe contains no newlines. */ - if (n_lines == 0) - goto free_lbuffers; - - /* Count the incomplete line on files that don't end with a newline. */ - if (last->buffer[last->nbytes - 1] != '\n') { - ++last->nlines; - ++total_lines; - } + if(pipe && (direction<0)) + bs++; + bytes_read=bs-startpoint; + memcpy(&buffer[0],&buffer[startpoint],bytes_read); - /* Run through the list, printing lines. First, skip over unneeded - buffers. */ - for (tmp = first; total_lines - tmp->nlines > n_lines; tmp = tmp->next) - total_lines -= tmp->nlines; - - /* Find the correct beginning, then print the rest of the file. */ - if (total_lines > n_lines) { - char *cp; - - /* Skip `total_lines' - `n_lines' newlines. We made sure that - `total_lines' - `n_lines' <= `tmp->nlines'. */ - cp = tmp->buffer; - for (i = total_lines - n_lines; i; --i) - while (*cp++ != '\n') - /* Do nothing. */ ; - i = cp - tmp->buffer; - } else - i = 0; - XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i); - - for (tmp = tmp->next; tmp; tmp = tmp->next) - XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes); - - free_lbuffers: - while (first) { - tmp = first->next; - free((char *) first); - first = tmp; - } - return errors; -} - -/* Print the last N_BYTES characters from the end of pipe FD. - This is a stripped down version of pipe_lines. - Return 0 if successful, 1 if an error occurred. */ - -static int pipe_bytes(const char *filename, int fd, off_t n_bytes) -{ - struct charbuffer { - int nbytes; - char buffer[BUFSIZ]; - struct charbuffer *next; - }; - typedef struct charbuffer CBUFFER; - CBUFFER *first, *last, *tmp; - int i; /* Index into buffers. */ - int total_bytes = 0; /* Total characters in all buffers. */ - int errors = 0; - - first = last = (CBUFFER *) xmalloc(sizeof(CBUFFER)); - first->nbytes = 0; - first->next = NULL; - tmp = (CBUFFER *) xmalloc(sizeof(CBUFFER)); - - /* Input is always read into a fresh buffer. */ - while ((tmp->nbytes = fullRead(fd, tmp->buffer, BUFSIZ)) > 0) { - tmp->next = NULL; - - total_bytes += tmp->nbytes; - /* If there is enough room in the last buffer read, just append the new - one to it. This is because when reading from a pipe, `nbytes' can - often be very small. */ - if (tmp->nbytes + last->nbytes < BUFSIZ) { - memcpy(&last->buffer[last->nbytes], tmp->buffer, tmp->nbytes); - last->nbytes += tmp->nbytes; - } else { - /* If there's not enough room, link the new buffer onto the end of - the list, then either free up the oldest buffer for the next - read if that would leave enough characters, or else malloc a new - one. Some compaction mechanism is possible but probably not - worthwhile. */ - last = last->next = tmp; - if (total_bytes - first->nbytes > n_bytes) { - tmp = first; - total_bytes -= first->nbytes; - first = first->next; - } else { - tmp = (CBUFFER *) xmalloc(sizeof(CBUFFER)); - } + bs=BUFSIZ; + while (1) { + if((filelocation>0 || pipe)){ + write(1,buffer,bytes_read); } - } - if (tmp->nbytes == -1) { - detailed_error(0, errno, "%s", filename); - errors = 1; - free((char *) tmp); - goto free_cbuffers; - } - - free((char *) tmp); - - /* Run through the list, printing characters. First, skip over unneeded - buffers. */ - for (tmp = first; total_bytes - tmp->nbytes > n_bytes; tmp = tmp->next) - total_bytes -= tmp->nbytes; - - /* Find the correct beginning, then print the rest of the file. - We made sure that `total_bytes' - `n_bytes' <= `tmp->nbytes'. */ - if (total_bytes > n_bytes) - i = total_bytes - n_bytes; - else - i = 0; - XWRITE(STDOUT_FILENO, &tmp->buffer[i], tmp->nbytes - i); - - for (tmp = tmp->next; tmp; tmp = tmp->next) - XWRITE(STDOUT_FILENO, tmp->buffer, tmp->nbytes); - - free_cbuffers: - while (first) { - tmp = first->next; - free((char *) first); - first = tmp; - } - return errors; -} - -/* Skip N_BYTES characters from the start of pipe FD, and print - any extra characters that were read beyond that. - Return 1 on error, 0 if ok. */ - -static int start_bytes(const char *filename, int fd, off_t n_bytes) -{ - char buffer[BUFSIZ]; - int bytes_read = 0; - - while (n_bytes > 0 && (bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) - n_bytes -= bytes_read; - if (bytes_read == -1) { - detailed_error(0, errno, "%s", filename); - return 1; - } else if (n_bytes < 0) - XWRITE(STDOUT_FILENO, &buffer[bytes_read + n_bytes], -n_bytes); - return 0; -} - -/* Skip N_LINES lines at the start of file or pipe FD, and print - any extra characters that were read beyond that. - Return 1 on error, 0 if ok. */ - -static int start_lines(const char *filename, int fd, long int n_lines) -{ - char buffer[BUFSIZ]; - int bytes_read = 0; - int bytes_to_skip = 0; - - while (n_lines && (bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) { - bytes_to_skip = 0; - while (bytes_to_skip < bytes_read) - if (buffer[bytes_to_skip++] == '\n' && --n_lines == 0) + bytes_read = read(fd, buffer, bs); + filelocation+=bytes_read; + if (bytes_read <= 0) { + if (!follow) { + close(fd); break; - } - if (bytes_read == -1) { - detailed_error(0, errno, "%s", filename); - return 1; - } else if (bytes_to_skip < bytes_read) { - XWRITE(STDOUT_FILENO, &buffer[bytes_to_skip], - bytes_read - bytes_to_skip); - } - return 0; -} - -/* Display file FILENAME from the current position in FD to the end. - If `forever' is nonzero, keep reading from the end of the file - until killed. Return the number of bytes read from the file. */ - -static long dump_remainder(const char *filename, int fd) -{ - char buffer[BUFSIZ]; - int bytes_read; - long total; - - total = 0; - output: - while ((bytes_read = fullRead(fd, buffer, BUFSIZ)) > 0) { - XWRITE(STDOUT_FILENO, buffer, bytes_read); - total += bytes_read; - } - if (bytes_read == -1) - detailed_error(EXIT_FAILURE, errno, "%s", filename); - if (forever) { - fflush(stdout); - sleep(1); - goto output; - } else { - if (forever_multiple) - fflush(stdout); - } - - return total; -} - -/* Tail NFILES (>1) files forever until killed. The file names are in - NAMES. The open file descriptors are in `file_descs', and the size - at which we stopped tailing them is in `file_sizes'. We loop over - each of them, doing an fstat to see if they have changed size. If - none of them have changed size in one iteration, we sleep for a - second and try again. We do this until the user interrupts us. */ - -static void tail_forever(char **names, int nfiles) -{ - int last; - - last = -1; - - while (1) { - int i; - int changed; - - changed = 0; - for (i = 0; i < nfiles; i++) { - struct stat stats; - - if (file_descs[i] < 0) - continue; - if (fstat(file_descs[i], &stats) < 0) { - detailed_error(0, errno, "%s", names[i]); - file_descs[i] = -1; - continue; - } - if (stats.st_size == file_sizes[i]) - continue; - - /* This file has changed size. Print out what we can, and - then keep looping. */ - - changed = 1; - - if (stats.st_size < file_sizes[i]) { - write_header(names[i], "file truncated"); - last = i; - lseek(file_descs[i], stats.st_size, SEEK_SET); - file_sizes[i] = stats.st_size; - continue; - } - - if (i != last) { - if (print_headers) - write_header(names[i], NULL); - last = i; } - file_sizes[i] += dump_remainder(names[i], file_descs[i]); + sleep(sleep_int); } - - /* If none of the files changed size, sleep. */ - if (!changed) - sleep(1); - } -} - -/* Output the last N_BYTES bytes of file FILENAME open for reading in FD. - Return 0 if successful, 1 if an error occurred. */ - -static int tail_bytes(const char *filename, int fd, off_t n_bytes) -{ - struct stat stats; - - /* FIXME: resolve this like in dd.c. */ - /* Use fstat instead of checking for errno == ESPIPE because - lseek doesn't work on some special files but doesn't return an - error, either. */ - if (fstat(fd, &stats)) { - detailed_error(0, errno, "%s", filename); - return 1; - } - - if (from_start) { - if (S_ISREG(stats.st_mode)) - lseek(fd, n_bytes, SEEK_CUR); - else if (start_bytes(filename, fd, n_bytes)) - return 1; - dump_remainder(filename, fd); - } else { - if (S_ISREG(stats.st_mode)) { - off_t current_pos, end_pos; - size_t bytes_remaining; - - if ((current_pos = lseek(fd, (off_t) 0, SEEK_CUR)) != -1 - && (end_pos = lseek(fd, (off_t) 0, SEEK_END)) != -1) { - off_t diff; - - /* Be careful here. The current position may actually be - beyond the end of the file. */ - bytes_remaining = (diff = - end_pos - current_pos) < 0 ? 0 : diff; - } else { - detailed_error(0, errno, "%s", filename); - return 1; - } - - if (bytes_remaining <= n_bytes) { - /* From the current position to end of file, there are no - more bytes than have been requested. So reposition the - file pointer to the incoming current position and print - everything after that. */ - lseek(fd, current_pos, SEEK_SET); - } else { - /* There are more bytes remaining than were requested. - Back up. */ - lseek(fd, -n_bytes, SEEK_END); - } - dump_remainder(filename, fd); - } else - return pipe_bytes(filename, fd, n_bytes); + usleep(sleep_int * 1000); } + if (buffer) + free(buffer); return 0; } -/* Output the last N_LINES lines of file FILENAME open for reading in FD. - Return 0 if successful, 1 if an error occurred. */ - -static int tail_lines(const char *filename, int fd, long int n_lines) +void add_file(char *name) { - struct stat stats; - off_t length; - - if (fstat(fd, &stats)) { - detailed_error(0, errno, "%s", filename); - return 1; - } - - if (from_start) { - if (start_lines(filename, fd, n_lines)) - return 1; - dump_remainder(filename, fd); - } else { - /* Use file_lines only if FD refers to a regular file with - its file pointer positioned at beginning of file. */ - /* FIXME: adding the lseek conjunct is a kludge. - Once there's a reasonable test suite, fix the true culprit: - file_lines. file_lines shouldn't presume that the input - file pointer is initially positioned to beginning of file. */ - if (S_ISREG(stats.st_mode) - && lseek(fd, (off_t) 0, SEEK_CUR) == (off_t) 0) { - length = lseek(fd, (off_t) 0, SEEK_END); - if (length != 0 && file_lines(filename, fd, n_lines, length)) - return 1; - dump_remainder(filename, fd); - } else - return pipe_lines(filename, fd, n_lines); - } - return 0; + ++n_files; + files = realloc(files, n_files); + files[n_files - 1] = (char *) malloc(strlen(name) + 1); + strcpy(files[n_files - 1], name); } -/* Display the last N_UNITS units of file FILENAME, open for reading - in FD. - Return 0 if successful, 1 if an error occurred. */ -static int tail(const char *filename, int fd, off_t n_units) +int tail_main(int argc, char **argv) { - if (count_lines) - return tail_lines(filename, fd, (long) n_units); - else - return tail_bytes(filename, fd, n_units); -} - -/* Display the last N_UNITS units of file FILENAME. - "-" for FILENAME means the standard input. - FILENUM is this file's index in the list of files the user gave. - Return 0 if successful, 1 if an error occurred. */ - -static int tail_file(const char *filename, off_t n_units, int filenum) -{ - int fd, errors; - struct stat stats; - - if (!strcmp(filename, "-")) { - have_read_stdin = 1; - filename = "standard input"; - if (print_headers) - write_header(filename, NULL); - errors = tail(filename, 0, n_units); - if (forever_multiple) { - if (fstat(0, &stats) < 0) { - detailed_error(0, errno, "standard input"); - errors = 1; - } else if (!S_ISREG(stats.st_mode)) { - detailed_error(0, 0, - "standard input: cannot follow end of non-regular file"); - errors = 1; - } - if (errors) - file_descs[filenum] = -1; - else { - file_descs[filenum] = 0; - file_sizes[filenum] = stats.st_size; - } - } - } else { - /* Not standard input. */ - fd = open(filename, O_RDONLY); - if (fd == -1) { - if (forever_multiple) - file_descs[filenum] = -1; - detailed_error(0, errno, "%s", filename); - errors = 1; - } else { - if (print_headers) - write_header(filename, NULL); - errors = tail(filename, fd, n_units); - if (forever_multiple) { - if (fstat(fd, &stats) < 0) { - detailed_error(0, errno, "%s", filename); - errors = 1; - } else if (!S_ISREG(stats.st_mode)) { - detailed_error(0, 0, - "%s: cannot follow end of non-regular file", - filename); - errors = 1; - } - if (errors) { - close(fd); - file_descs[filenum] = -1; - } else { - file_descs[filenum] = fd; - file_sizes[filenum] = stats.st_size; - } - } else { - if (close(fd)) { - detailed_error(0, errno, "%s", filename); - errors = 1; - } - } + int show_headers = 1; + int test; + int c; + int nargs=0; + char **argn=NULL; + + opterr = 0; + + for(c=0;c<argc;c++){ + test=atoi(argv[c]); + if(test){ + units=test; + if(units<0) + units=units-1; + }else{ + nargs++; + argn = realloc(argn, nargs); + argn[nargs - 1] = (char *) malloc(strlen(argv[c]) + 1); + strcpy(argn[nargs - 1], argv[c]); } } + while (1) { + int opt_index = 0; - return errors; -} - -extern int tail_main(int argc, char **argv) -{ - int stopit = 0; - enum header_mode header_mode = multiple_files; - int exit_status = 0; - - /* If from_start, the number of items to skip before printing; otherwise, - the number of items at the end of the file to print. Initially, -1 - means the value has not been set. */ - off_t n_units = -1; - int n_files; - char **file; - - program_name = argv[0]; - have_read_stdin = 0; - count_lines = 1; - forever = forever_multiple = from_start = print_headers = 0; - - /* Parse any options */ - //fprintf(stderr, "argc=%d, argv=%s\n", argc, *argv); - while (--argc > 0 && (**(++argv) == '-' || **argv == '+')) { - if (**argv == '+') { - from_start = 1; - } - stopit = 0; - while (stopit == 0 && *(++(*argv))) { - switch (**argv) { - case 'c': - count_lines = 0; - - if (--argc < 1) { - usage(tail_usage); - } - n_units = getNum(*(++argv)); - stopit = 1; - break; - - case 'f': - forever = 1; - break; + c = getopt_long_only(nargs, argn, + "c:fhn:s:qv", NULL, &opt_index); + if (c == -1) + break; + switch (c) { - case 'n': - count_lines = 1; +#ifndef BB_FEATURE_SIMPLE_TAIL - if (--argc < 1) { + case 'c': + unit_type = BYTES; + test = atoi(optarg); + if(test==0) + usage(tail_usage); + if(optarg[strlen(optarg)-1]>'9') { + switch (optarg[strlen(optarg)-1]) { + case 'b': + test *= 512; + break; + case 'k': + test *= 1024; + break; + case 'm': + test *= (1024 * 1024); + break; + default: + fprintf(stderr,"Size must be b,k, or m."); usage(tail_usage); } - n_units = atol(*(++argv)); - stopit = 1; - break; - - case 'q': - header_mode = never; - break; - - case 'v': - header_mode = always; - break; - - default: - usage(tail_usage); } + if(optarg[0]=='+') + units=test+1; + else + units=-(test+1); + break; + case 'q': + show_headers = 0; + break; + case 's': + sleep_int = atoi(optarg); + if(sleep_int<1) + sleep_int=1; + break; + case 'v': + verbose = 1; + break; +#endif + case 'f': + follow = 1; + break; + case 'h': + usage(tail_usage); + break; + case 'n': + test = atoi(optarg); + if (test) { + if (optarg[0] == '+') + units = test; + else + units = -(test+1); + } else + usage(tail_usage); + break; + default: + errorMsg("\nUnknown arg: %c.\n\n",c); + usage(tail_usage); } } - - - if (n_units == -1) - n_units = DEFAULT_N_LINES; - - /* To start printing with item N_UNITS from the start of the file, skip - N_UNITS - 1 items. `tail +0' is actually meaningless, but for Unix - compatibility it's treated the same as `tail +1'. */ - if (from_start) { - if (n_units) - --n_units; - } - - n_files = argc; - file = argv; - - if (n_files > 1 && forever) { - forever_multiple = 1; - forever = 0; - file_descs = (int *) xmalloc(n_files * sizeof(int)); - - file_sizes = (off_t *) xmalloc(n_files * sizeof(off_t)); - } - - if (header_mode == always - || (header_mode == multiple_files && n_files > 1)) - print_headers = 1; - - if (n_files == 0) { - exit_status |= tail_file("-", n_units, 0); - } else { - int i; - - for (i = 0; i < n_files; i++) - exit_status |= tail_file(file[i], n_units, i); - - if (forever_multiple) - tail_forever(file, n_files); - } - - if (have_read_stdin && close(0) < 0) - detailed_error(EXIT_FAILURE, errno, "-"); - if (fclose(stdout) == EOF) - detailed_error(EXIT_FAILURE, errno, "write error"); - exit(exit_status == 0 ? EXIT_SUCCESS : EXIT_FAILURE); + while (optind < nargs) { + if (!strcmp(argn[optind], "-")) + add_file(STDIN); + else + add_file(argn[optind]); + optind++; + } + if(units==0) + units=-11; + if(units>0) + units--; + if (n_files == 0) + add_file(STDIN); + if (n_files == 1) +#ifndef BB_FEATURE_SIMPLE_TAIL + if (!verbose) +#endif + show_headers = 0; + for (test = 0; test < n_files; test++) { + if (show_headers) + printf("==> %s <==\n", files[test]); + tail_stream(test); + } + if(files) + free(files); + if(argn) + free(argn); + return 0; } - -#endif +/* +Local Variables: +c-file-style: "linux" +c-basic-offset: 4 +tab-width: 4 +End: +*/ |