FOPEN(3S)                                               FOPEN(3S)

     NAME
          fopen, freopen, fdopen - open a stream

     SYNOPSIS
          #include <stdio.h>

          FILE *fopen(filename, type)
          char *filename, *type;

          FILE *freopen(filename, type, stream)
          char *filename, *type;
          FILE *stream;

          FILE *fdopen(fildes, type)
          char *type;

     DESCRIPTION
          Fopen opens the file named by filename and associates a
          stream with it.  Fopen returns a pointer to be used to iden-
          tify the stream in subsequent operations.

          Type is a character string having one of the following val-
          ues:

          "r"  open for reading

          "w"  create for writing

          "a"  append: open for writing at end of file, or create for
               writing

          Freopen substitutes the named file in place of the open
          stream. It returns the original value of stream. The origi-
          nal stream is closed.  Freopen is typically used to attach
          the preopened constant names, `stdin', `stdout', `stderr',
          to specified files.

          Fdopen associates a stream with a file descriptor obtained
          from open, dup, creat, or pipe(2). The type of the stream
          must agree with the mode of the open file.

     SEE ALSO
          open(2), fclose(3)

     DIAGNOSTICS
          Fopen and freopen return the pointer NULL if filename cannot
          be accessed.

     BUGS
          Fdopen is not portable to systems other than UNIX.