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author | An-Cheng Huang <ancheng@vyatta.com> | 2007-11-12 13:06:02 -0800 |
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committer | An-Cheng Huang <ancheng@vyatta.com> | 2007-11-12 13:06:02 -0800 |
commit | b7fc9e0f6d6105ba2203f219743d4b269415e84b (patch) | |
tree | ef6586dfc62798c2b17487b443864699aca55f31 /examples/loadables/head.c | |
download | vyatta-bash-b7fc9e0f6d6105ba2203f219743d4b269415e84b.tar.gz vyatta-bash-b7fc9e0f6d6105ba2203f219743d4b269415e84b.zip |
initial import from bash_3.1dfsg.orig.tar.gz
Diffstat (limited to 'examples/loadables/head.c')
-rw-r--r-- | examples/loadables/head.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/examples/loadables/head.c b/examples/loadables/head.c new file mode 100644 index 0000000..9052689 --- /dev/null +++ b/examples/loadables/head.c @@ -0,0 +1,143 @@ +/* head - copy first part of files. */ + +/* See Makefile for compilation details. */ + +#include "config.h" + +#include "bashtypes.h" +#include "posixstat.h" +#include "filecntl.h" + +#if defined (HAVE_UNISTD_H) +# include <unistd.h> +#endif + +#include "bashansi.h" + +#include <stdio.h> +#include <errno.h> +#include "chartypes.h" + +#include "builtins.h" +#include "shell.h" +#include "bashgetopt.h" + +#if !defined (errno) +extern int errno; +#endif + +static void +munge_list (list) + WORD_LIST *list; +{ + WORD_LIST *l, *nl; + WORD_DESC *wd; + char *arg; + + for (l = list; l; l = l->next) + { + arg = l->word->word; + if (arg[0] != '-' || arg[1] == '-' || (DIGIT(arg[1]) == 0)) + return; + /* We have -[0-9]* */ + wd = make_bare_word (arg+1); + nl = make_word_list (wd, l->next); + l->word->word[1] = 'n'; + l->word->word[2] = '\0'; + l->next = nl; + l = nl; /* skip over new argument */ + } +} + +static int +file_head (fp, cnt) + FILE *fp; + int cnt; +{ + int ch; + + while (cnt--) + { + while ((ch = getc (fp)) != EOF) + { + if (putchar (ch) == EOF) + { + builtin_error ("write error: %s", strerror (errno)); + return EXECUTION_FAILURE; + } + if (ch == '\n') + break; + } + } +} + +head_builtin (list) + WORD_LIST *list; +{ + int nline, opt, rval; + WORD_LIST *l; + FILE *fp; + + char *t; + + munge_list (list); /* change -num into -n num */ + + reset_internal_getopt (); + nline = 10; + while ((opt = internal_getopt (list, "n:")) != -1) + { + switch (opt) + { + case 'n': + nline = atoi (list_optarg); + if (nline <= 0) + { + builtin_error ("bad line count: %s", list_optarg); + return (EX_USAGE); + } + break; + default: + builtin_usage (); + return (EX_USAGE); + } + } + list = loptend; + + if (list == 0) + return (file_head (stdin, nline)); + + for (rval = EXECUTION_SUCCESS, opt = 1, l = list; l; l = l->next) + { + fp = fopen (l->word->word, "r"); + if (fp == NULL) + { + builtin_error ("%s: %s", l->word->word, strerror (errno)); + continue; + } + if (list->next) /* more than one file */ + { + printf ("%s==> %s <==\n", opt ? "" : "\n", l->word->word); + opt = 0; + } + rval = file_head (fp, nline); + fclose (fp); + } + + return (rval); +} + +char *head_doc[] = { + "Copy the first N lines from the input files to the standard output.", + "N is supplied as an argument to the `-n' option. If N is not given,", + "the first ten lines are copied.", + (char *)NULL +}; + +struct builtin head_struct = { + "head", /* builtin name */ + head_builtin, /* function implementing the builtin */ + BUILTIN_ENABLED, /* initial flags for builtin */ + head_doc, /* array of long documentation strings. */ + "head [-n num] [file ...]", /* usage synopsis; becomes short_doc */ + 0 /* reserved for internal use */ +}; |