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RLE_OPEN_F(3)         DragonFly Library Functions Manual         RLE_OPEN_F(3)


NAME

       rle_open_f - Open a binary file for input or output with defaults.
       rle_open_f_noexit - Returns error code instead of exiting.


SYNOPSIS

       FILE *rle_open_f( prog_name, file_name, mode )
       char *prog_name, *file_name, *mode;

       FILE *rle_open_f_noexit( prog_name, file_name, mode )
       char *prog_name, *file_name, *mode;


DESCRIPTION

       The function rle_open_f is provided to simplify the task of opening
       files in toolkit programs.  It works similarly to fopen(3), but it also
       provides error checking and messages, and default values for input and
       output.  If the specified file_name cannot be opened, an error message
       is printed and the program exits.  A variant rle_open_f_noexit is
       provided which will return NULL if the file cannot be opened.  An error
       message is still printed.

       On those systems which require it, a 'b' will be appended to the mode
       string so that the file will be opened in binary mode.

       If the file_name is NULL or "-", then stdin will be returned for input
       (mode "r") files and stdout will be returned for output (mode "w" or
       "a") files.

       The following two options are available only on systems supporting
       pipes.  If the file_name starts with a "|" character, then the rest of
       the file name will be taken as a sh(1) command.  If mode is "r", a pipe
       from the output of the sh command will be returned.  If mode is "w" or
       "a", a pipe to the input of the sh command will be returned.

       If the file_name ends with the suffix ".Z" (and does not start with
       "|"), then the compress(1) program will be invoked to uncompress (mode
       "r") or compress (mode "w" or "a") the file.  The file descriptor
       returned by rle_open_f will be a pipe from or to the compress program.


SEE ALSO

       fopen(3), popen(3), compress(1).


AUTHOR

       Gerald Winter
       Spencer W. Thomas
       University of Michigan


BUGS

       If the command invoked via popen does not exist, the popen still
       returns successfully, and the underlying sh prints an error message.

       There is no way of telling that a particular FILE pointer has been
       created by popen, so it isn't possible to cleanly close the pipe with
       pclose.  In fact, the eventual output file may not even exist by the
       time the program exits.

4th Berkeley Distribution           2/2/87                       RLE_OPEN_F(3)

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