UnGetC

Makes a char available for reading again. (buffered) (V36)

Pushes the character specified back into the input buffer. Every time you use a buffered read function, you can always push back 1 character. You may be able to push back more, though it is not recommended, since there is no guarantee on how many can be pushed back at a given moment.

Passing -1 for the character will cause the last character read to be pushed back. If the last character read was an EOF, the next character read will be an EOF.

Note:

UnGetC can be used to make sure that a FileHandle is set up

as a read FileHandle. This is only of importance if you are writing a shell, and must manipulate the FileHandle's buffer.

fh

FileHandle to use for buffered I/O

character

character to push back or -1. -1 indicates failure; call IoErr() to find out why UnGetC() has failed.

value

character pushed back, or FALSE if the character cannot be pushed back.

In V36, UnGetC(fh,-1) after an EOF would not cause the next character read to be an EOF. This was fixed for V37.

FGetC(), FPutC(), Flush(), IoErr()