Open System Services Library Calls Reference Manual (G06.29+, H06.08+, J06.03+)

ungetc(3) OSS Library Calls Reference Manual

NAME

ungetc - Pushes a character back into the input stream

LIBRARY

G-series native Guardian processes: $SYSTEM.SYSnn.ZCRTLSRL

G-series native OSS processes: /G/system/sysnn/zcrtlsrl

H-series and J-series native Guardian processes: $SYSTEM.ZDLLnnn.ZCRTLDLL

32-bit H-series and J-series OSS processes: /G/system/zdllnnn/zcrtldll

64-bit H-series and J-series OSS processes: /G/system/zdllnnn/ycrtldll

SYNOPSIS

#include <stdio.h>

int ungetc(

int c,

FILE *stream);

PARAMETERS

c Speciﬁes a byte to be inserted into the input stream.

stream Speciﬁes the input stream.

DESCRIPTION

The ungetc( ) function converts the byte speciﬁed by the c parameter into an unsigned char and

inserts it into the buffer associated with the input stream speciﬁed by the stream parameter. This

causes the next call to the getc( ) function to return c.

If the c parameter has a value equal to EOF, the ungetc( ) function does not place anything in the

buffer and the input stream is unchanged.

You can always push one byte back onto a stream. The fseek( ) subroutine erases all memory of

inserted characters.

NOTES

The ungetc( ) function does not have any effect on the external storage corresponding to the

stream.

RETURN VALUES

The ungetc( ) returns c if it succeeds in inserting the byte in the stream. Otherwise, it returns a

value of EOF.

ERRORS

None. This function does not set errno.

RELATED INFORMATION

Functions: fseek(3), getc(3), getwc(3), setbuf(3), ungetwc(3).

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