libf2c/libI77/endfile.c

   1 #include "config.h"
   2 #include "f2c.h"
   3 #include "fio.h"
   4
   5 #include <sys/types.h>
   6 #include <unistd.h>
   7
   8 #undef abs
   9 #undef min
  10 #undef max
  11 #include <stdlib.h>
  12 #include <string.h>
  13
  14 extern char *f__r_mode[], *f__w_mode[];
  15
  16 integer
  17 f_end (alist * a)
  18 {
  19   unit *b;
  20   FILE *tf;
  21
  22   if (f__init & 2)
  23     f__fatal (131, "I/O recursion");
  24   if (a->aunit >= MXUNIT || a->aunit < 0)
  25     err (a->aerr, 101, "endfile");
  26   b = &f__units[a->aunit];
  27   if (b->ufd == NULL)
  28     {
  29       char nbuf[10];
  30       sprintf (nbuf, "fort.%ld", (long) a->aunit);
  31       if ((tf = fopen (nbuf, f__w_mode[0])))
  32         fclose (tf);
  33       return (0);
  34     }
  35   b->uend = 1;
  36   return (b->useek ? t_runc (a) : 0);
  37 }
  38
  39 #ifndef HAVE_FTRUNCATE
  40 static int
  41 copy (FILE * from, register long len, FILE * to)
  42 {
  43   int len1;
  44   char buf[BUFSIZ];
  45
  46   while (fread (buf, len1 = len > BUFSIZ ? BUFSIZ : (int) len, 1, from))
  47     {
  48       if (!fwrite (buf, len1, 1, to))
  49         return 1;
  50       if ((len -= len1) <= 0)
  51         break;
  52     }
  53   return 0;
  54 }
  55 #endif /* !defined(HAVE_FTRUNCATE) */
  56
  57 int
  58 t_runc (alist * a)
  59 {
  60   off_t loc, len;
  61   unit *b;
  62   int rc;
  63   FILE *bf;
  64 #ifndef HAVE_FTRUNCATE
  65   FILE *tf;
  66 #endif /* !defined(HAVE_FTRUNCATE) */
  67
  68   b = &f__units[a->aunit];
  69   if (b->url)
  70     return (0);                 /*don't truncate direct files */
  71   loc = FTELL (bf = b->ufd);
  72   FSEEK (bf, 0, SEEK_END);
  73   len = FTELL (bf);
  74   if (loc >= len || b->useek == 0 || b->ufnm == NULL)
  75     return (0);
  76 #ifndef HAVE_FTRUNCATE
  77   rc = 0;
  78   fclose (b->ufd);
  79   if (!loc)
  80     {
  81       if (!(bf = fopen (b->ufnm, f__w_mode[b->ufmt])))
  82         rc = 1;
  83       if (b->uwrt)
  84         b->uwrt = 1;
  85       goto done;
  86     }
  87   if (!(bf = fopen (b->ufnm, f__r_mode[0])) || !(tf = tmpfile ()))
  88     {
  89 #ifdef NON_UNIX_STDIO
  90     bad:
  91 #endif
  92       rc = 1;
  93       goto done;
  94     }
  95   if (copy (bf, loc, tf))
  96     {
  97     bad1:
  98       rc = 1;
  99       goto done1;
 100     }
 101   if (!(bf = freopen (b->ufnm, f__w_mode[0], bf)))
 102     goto bad1;
 103   FSEEK (tf, 0, SEEK_SET);
 104   if (copy (tf, loc, bf))
 105     goto bad1;
 106   b->uwrt = 1;
 107   b->urw = 2;
 108 #ifdef NON_UNIX_STDIO
 109   if (b->ufmt)
 110     {
 111       fclose (bf);
 112       if (!(bf = fopen (b->ufnm, f__w_mode[3])))
 113         goto bad;
 114       FSEEK (bf, 0, SEEK_END);
 115       b->urw = 3;
 116     }
 117 #endif
 118 done1:
 119   fclose (tf);
 120 done:
 121   f__cf = b->ufd = bf;
 122 #else /* !defined(HAVE_FTRUNCATE) */
 123   fflush (b->ufd);
 124   rc = ftruncate (fileno (b->ufd), loc);
 125   FSEEK (bf, loc, SEEK_SET);
 126 #endif /* !defined(HAVE_FTRUNCATE) */
 127   if (rc)
 128     err (a->aerr, 111, "endfile");
 129   return 0;
 130 }