diff options
author | Manuel Novoa III <mjn3@codepoet.org> | 2003-03-19 12:13:01 +0300 |
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committer | Manuel Novoa III <mjn3@codepoet.org> | 2003-03-19 12:13:01 +0300 |
commit | cad5364599eb5062d59e0c397ed638ddd61a8d5d (patch) | |
tree | a318d0f03aa076c74b576ea45dc543a5669e8e91 /coreutils/head.c | |
parent | e01f9662a5bd5d91be4f6b3941b57fff73cd5af1 (diff) |
Major coreutils update.
Diffstat (limited to 'coreutils/head.c')
-rw-r--r-- | coreutils/head.c | 154 |
1 files changed, 95 insertions, 59 deletions
diff --git a/coreutils/head.c b/coreutils/head.c index ad21e1b95..dab4de11b 100644 --- a/coreutils/head.c +++ b/coreutils/head.c @@ -1,9 +1,8 @@ /* vi: set sw=4 ts=4: */ /* - * Mini head implementation for busybox + * head implementation for busybox * - * Copyright (C) 1999 by Lineo, inc. and John Beppu - * Copyright (C) 1999,2000,2001 by John Beppu <beppu@codepoet.org> + * Copyright (C) 2003 Manuel Novoa III <mjn3@codepoet.org> * * 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 @@ -21,82 +20,119 @@ * */ +/* BB_AUDIT SUSv3 compliant */ +/* BB_AUDIT GNU compatible -c, -q, and -v options in 'fancy' configuration. */ +/* http://www.opengroup.org/onlinepubs/007904975/utilities/head.html */ + #include <stdio.h> -#include <getopt.h> #include <stdlib.h> -#include <string.h> +#include <limits.h> #include <ctype.h> +#include <unistd.h> #include "busybox.h" -static int head(int len, FILE *fp) -{ - int i; - char *input; +static const char head_opts[] = + "n:" +#ifdef CONFIG_FEATURE_FANCY_HEAD + "c:qv" +#endif + ; - for (i = 0; i < len; i++) { - if ((input = get_line_from_file(fp)) == NULL) - break; - fputs(input, stdout); - free(input); - } - return 0; -} +static const char header_fmt_str[] = "\n==> %s <==\n"; -/* BusyBoxed head(1) */ int head_main(int argc, char **argv) { + unsigned long count = 10; + unsigned long i; +#ifdef CONFIG_FEATURE_FANCY_HEAD + int count_bytes = 0; + int header_threshhold = 1; +#endif + FILE *fp; - int need_headers, opt, len = 10, status = EXIT_SUCCESS; + const char *fmt; + char *p; + int opt; + int c; + int retval = EXIT_SUCCESS; - if (( argc >= 2 ) && ( argv [1][0] == '-' ) && isdigit ( argv [1][1] )) { - len = atoi ( &argv [1][1] ); - optind = 2; + /* Allow legacy syntax of an initial numeric option without -n. */ + if ((argc > 1) && (argv[1][0] == '-') + /* && (isdigit)(argv[1][1]) */ + && (((unsigned int)(argv[1][1] - '0')) <= 9) + ) { + --argc; + ++argv; + p = (*argv) + 1; + goto GET_COUNT; } - /* parse argv[] */ - while ((opt = getopt(argc, argv, "n:")) > 0) { - switch (opt) { - case 'n': - len = atoi(optarg); - if (len >= 0) + while ((opt = getopt(argc, argv, head_opts)) > 0) { + switch(opt) { +#ifdef CONFIG_FEATURE_FANCY_HEAD + case 'q': + header_threshhold = INT_MAX; + break; + case 'v': + header_threshhold = -1; break; - /* fallthrough */ - default: - show_usage(); + case 'c': + count_bytes = 1; + /* fall through */ +#endif + case 'n': + p = optarg; + GET_COUNT: + count = bb_xgetularg10(p); + break; + default: + bb_show_usage(); } } - /* get rest of argv[] or stdin if nothing's left */ - if (argv[optind] == NULL) { - head(len, stdin); - return status; - } + argv += optind; + if (!*argv) { + *--argv = "-"; + } - need_headers = optind != (argc - 1); - while (argv[optind]) { - if (strcmp(argv[optind], "-") == 0) { - fp = stdin; - argv[optind] = "standard input"; - } else { - if ((fp = wfopen(argv[optind], "r")) == NULL) - status = EXIT_FAILURE; - } - if (fp) { - if (need_headers) { - printf("==> %s <==\n", argv[optind]); + fmt = header_fmt_str + 1; +#ifdef CONFIG_FEATURE_FANCY_HEAD + if (argc - optind <= header_threshhold) { + header_threshhold = 0; + } +#else + if (argc <= optind + 1) { + fmt += 11; + } + /* Now define some things here to avoid #ifdefs in the code below. + * These should optimize out of the if conditions below. */ +#define header_threshhold 1 +#define count_bytes 0 +#endif + + do { + if ((fp = bb_wfopen_input(*argv)) != NULL) { + if (fp == stdin) { + *argv = (char *) bb_msg_standard_input; } - head(len, fp); - if (ferror(fp)) { - perror_msg("%s", argv[optind]); - status = EXIT_FAILURE; + if (header_threshhold) { + bb_printf(fmt, *argv); } - if (optind < argc - 1) - putchar('\n'); - if (fp != stdin) - fclose(fp); + i = count; + while (i && ((c = getc(fp)) != EOF)) { + if (count_bytes || (c == '\n')) { + --i; + } + putchar(c); + } + if (bb_fclose_nonstdin(fp)) { + bb_perror_msg("%s", *argv); /* Avoid multibyte problems. */ + retval = EXIT_FAILURE; + } + bb_xferror_stdout(); } - optind++; - } + fmt = header_fmt_str; + } while (*++argv); - return status; + bb_fflush_stdout_and_exit(retval); } |