newlib/libc/stdio64/tmpfile64.c

   1 /*
   2 FUNCTION
   3 <<tmpfile64>>---create a large temporary file
   4
   5 INDEX
   6         tmpfile64
   7 INDEX
   8         _tmpfile64_r
   9
  10 SYNOPSIS
  11         #include <stdio.h>
  12         FILE *tmpfile64(void);
  13
  14         FILE *_tmpfile64_r(void *<[reent]>);
  15
  16 DESCRIPTION
  17 Create a large temporary file (a file which will be deleted automatically),
  18 using a name generated by <<tmpnam>>.  The temporary file is opened with
  19 the mode <<"wb+">>, permitting you to read and write anywhere in it
  20 as a binary file (without any data transformations the host system may
  21 perform for text files).  The file may be larger than 2GB.
  22
  23 The alternate function <<_tmpfile64_r>> is a reentrant version.  The
  24 argument <[reent]> is a pointer to a reentrancy structure.
  25
  26 Both <<tmpfile64>> and <<_tmpfile64_r>> are only defined if __LARGE64_FILES
  27 is defined.
  28
  29 RETURNS
  30 <<tmpfile64>> normally returns a pointer to the temporary file.  If no
  31 temporary file could be created, the result is NULL, and <<errno>>
  32 records the reason for failure.
  33
  34 PORTABILITY
  35 <<tmpfile64>> is a glibc extension.
  36
  37 Supporting OS subroutines required: <<close>>, <<fstat>>, <<getpid>>,
  38 <<isatty>>, <<lseek64>>, <<open64>>, <<read>>, <<sbrk>>, <<write>>.
  39
  40 <<tmpfile64>> also requires the global pointer <<environ>>.
  41 */
  42
  43 #include <stdio.h>
  44 #include <reent.h>
  45 #include <errno.h>
  46 #include <fcntl.h>
  47 #include <sys/stat.h>
  48
  49 #ifndef O_BINARY
  50 # define O_BINARY 0
  51 #endif
  52
  53 #ifdef __LARGE64_FILES
  54
  55 FILE *
  56 _tmpfile64_r (struct _reent *ptr)
  57 {
  58   FILE *fp;
  59   int e;
  60   char *f;
  61   char buf[L_tmpnam];
  62   int fd;
  63
  64   do
  65   {
  66      if ((f = _tmpnam_r (ptr, buf)) == NULL)
  67         return NULL;
  68       fd = _open64_r (ptr, f, O_RDWR | O_CREAT | O_EXCL | O_BINARY,
  69                       S_IRUSR | S_IWUSR);
  70   }
  71   while (fd < 0 && _REENT_ERRNO(ptr) == EEXIST);
  72   if (fd < 0)
  73     return NULL;
  74   fp = _fdopen64_r (ptr, fd, "wb+");
  75   e = _REENT_ERRNO(ptr);
  76   if (!fp)
  77     _close_r (ptr, fd);
  78   (void) _remove_r (ptr, f);
  79   _REENT_ERRNO(ptr) = e;
  80   return fp;
  81 }
  82
  83 #ifndef _REENT_ONLY
  84
  85 FILE *
  86 tmpfile64 (void)
  87 {
  88   return _tmpfile64_r (_REENT);
  89 }
  90
  91 #endif
  92
  93 #endif /* __LARGE64_FILES */