In the case of HFS file access, no additional padding is written to files and buffering is handled directly by OMVS.
JCC compiled programs conditionally link the I/O routines depending on the use of at least one JCC I/O library function. If the library has been combined with the program, the runtime automatically and silently attempts to open //DDN:STDIN, //DDN:STDOUT and //DDN:STDERR. These files are accessed with the following predefined handles:
Stream | Handle |
stdin | 0 |
stdout | 1 |
stderr | 2 |
Low level I/O routines set the thread-specific errno global variable when an error occurs.
_fmode may by updated to change the default open mode.
Routine | Use |
__bldl | Reports the files (member) block position |
_close | Closes a file |
_commit | Commit buffers (does nothing in this implementation.) |
_dup | Duplicate a file handle |
_dup2 | Duplicate a file handle to a specific handle |
_eof | Tests for the End Of File |
_filelength | Reports the length of a file (reads the entire file) |
__getdcb | Returns open dataset information |
__getdcba | Returns the address of a DCB for an open dataset |
_isatty | Checks for a Terminal device |
_lseek | Repositions to a location in a file |
__note | Reports the last read/written block position |
_open | Opens a file |
_read | Reads data from a file |
remove | Delete a file |
rename | Rename a file |
_setmode | Sets the translation mode |
__setstow | Sets aux. close information for member names |
_tell | Returns the current file position |
_unlink | Delete a file |
_write | Writes data to a file |