ungetc - returns a single character to the input buffer of the
given File
or to io::Output
ungetc(
ch)
ungetc(
file, ch)
file.ungetc(
ch)
Returns a single character to the input buffer of the given
file. If the file is not provided, the character will
be returned to io::Output
. The character
ch is always converted to Int
. In
text-mode, it will buffer the ch as a UTF-8 sequence. In
binary-mode, it will buffer the ch as an unsigned byte.
None
ArgCheck
for an incorrect number of arguments
TypeCheck
for a non-File
file or non-numeric ch
AccessCheck
for an attempt to access a closed
file
IoCheck
for other
miscellaneous I/O errors (see ferror)
// Use getchar/ungetc to peek ahead for EOF proc main() { var ch; ch = getchar(); while (ch != io::EOF) { ungetc(ch); var str = readstr(); "", str, '\n'; ch = getchar(); } }