examples/loadables/tee.c

   1 /* tee - duplicate standard input */
   2
   3 /* See Makefile for compilation details. */
   4
   5 #include "config.h"
   6
   7 #include "bashtypes.h"
   8 #include "posixstat.h"
   9 #include "filecntl.h"
  10
  11 #include <signal.h>
  12
  13 #if defined (HAVE_UNISTD_H)
  14 #  include <unistd.h>
  15 #endif
  16
  17 #include "bashansi.h"
  18
  19 #include <stdio.h>
  20 #include <errno.h>
  21
  22 #include "builtins.h"
  23 #include "shell.h"
  24 #include "bashgetopt.h"
  25
  26 #if !defined (errno)
  27 extern int errno;
  28 #endif
  29
  30 typedef struct flist {
  31   struct flist *next;
  32   int fd;
  33   char *fname;
  34 } FLIST;
  35
  36 static FLIST *tee_flist;
  37
  38 #define TEE_BUFSIZE     8192
  39
  40 extern int interrupt_immediately;
  41
  42 extern char *strerror ();
  43
  44 tee_builtin (list)
  45      WORD_LIST *list;
  46 {
  47   int opt, append, nointr, rval, fd, fflags;
  48   int n, nr, nw;
  49   FLIST *fl;
  50   char *buf, *bp;
  51
  52   char *t;
  53
  54   reset_internal_getopt ();
  55   append = nointr = 0;
  56   tee_flist = (FLIST *)NULL;
  57   while ((opt = internal_getopt (list, "ai")) != -1)
  58     {
  59       switch (opt)
  60         {
  61         case 'a':
  62           append = 1;
  63           break;
  64         case 'i':
  65           nointr = 1;
  66           break;
  67         default:
  68           builtin_usage ();
  69           return (EX_USAGE);
  70         }
  71     }
  72   list = loptend;
  73
  74   if (nointr == 0)
  75     interrupt_immediately++;
  76
  77   buf = xmalloc (TEE_BUFSIZE);
  78
  79   /* Initialize output file list. */
  80   fl = tee_flist = (FLIST *)xmalloc (sizeof(FLIST));
  81   tee_flist->fd = 1;
  82   tee_flist->fname = "stdout";
  83   tee_flist->next = (FLIST *)NULL;
  84
  85   /* Add file arguments to list of output files. */
  86   fflags = append ? O_WRONLY|O_CREAT|O_APPEND : O_WRONLY|O_CREAT|O_TRUNC;
  87   for (rval = EXECUTION_SUCCESS; list; list = list->next)
  88     {
  89       fd = open (list->word->word, fflags, 0666);
  90       if (fd < 0)
  91         {
  92           builtin_error ("%s: cannot open: %s", list->word->word, strerror (errno));
  93           rval = EXECUTION_FAILURE;
  94         }
  95       else
  96         {
  97           fl->next = (FLIST *)xmalloc (sizeof(FLIST));
  98           fl->next->fd = fd;
  99           fl->next->fname = list->word->word;
 100           fl = fl->next;
 101           fl->next = (FLIST *)NULL;
 102         }
 103     }
 104
 105   while ((nr = read(0, buf, TEE_BUFSIZE)) > 0)
 106     for (fl = tee_flist; fl; fl = fl->next)
 107       {
 108         n = nr;
 109         bp = buf;
 110         do
 111           {
 112             if ((nw = write (fl->fd, bp, n)) == -1)
 113               {
 114                 builtin_error ("%s: write error: %s", fl->fname, strerror (errno));
 115                 rval = EXECUTION_FAILURE;
 116                 break;
 117               }
 118             bp += nw;
 119           }
 120         while (n -= nw);
 121       }
 122   if (nr < 0)
 123     builtin_error ("read error: %s", strerror (errno));
 124
 125   /* Deallocate resources -- this is a builtin command. */
 126   tee_flist = tee_flist->next;          /* skip bogus close of stdout */
 127   while (tee_flist)
 128     {
 129       fl = tee_flist;
 130       if (close (fl->fd) < 0)
 131         {
 132           builtin_error ("%s: close_error: %s", fl->fname, strerror (errno));
 133           rval = EXECUTION_FAILURE;
 134         }
 135       tee_flist = tee_flist->next;
 136       free (fl);
 137     }
 138
 139   return (rval);
 140 }
 141
 142 char *tee_doc[] = {
 143         "Copy standard input to standard output, making a copy in each",
 144         "filename argument.  If the `-a' option is gived, the specified",
 145         "files are appended to, otherwise they are overwritten.  If the",
 146         "`-i' option is supplied, tee ignores interrupts.",
 147         (char *)NULL
 148 };
 149
 150 struct builtin tee_struct = {
 151         "tee",                  /* builtin name */
 152         tee_builtin,            /* function implementing the builtin */
 153         BUILTIN_ENABLED,        /* initial flags for builtin */
 154         tee_doc,                /* array of long documentation strings. */
 155         "tee [-ai] [file ...]", /* usage synopsis; becomes short_doc */
 156         0                       /* reserved for internal use */
 157 };