getc(3S)getc(3S)NAMEgetc(), getc_unlocked(), getchar(), getchar_unlocked(), fgetc(),
getw(), getw_unlocked() - get character or word from a stream file
Returns the next character (i.e., byte) from the named input
stream, as an unsigned character converted to an inte‐
ger. It also moves the file pointer, if defined, ahead
one character in stream. is defined as and are defined
both as macros and as functions.
Same as but is a function rather than a macro. is slower than
but it takes less space per invocation and its name can
be passed as an argument to a function.
returns the next word (i.e.,
in C) from the named input stream. increments the asso‐
ciated file pointer, if defined, to point to the next
word. The size of a word is the size of an integer and
varies from machine to machine. assumes no special
alignment in the file.
and are identical to and respectively except they do not perform any
internal locking of the stream for multithreaded applications.
gets character or word from a stream file.
and interfaces should be used by multithread applications which have
already used to acquire a mutual exclusion lock for the stream (see
After or is applied to a stream, the stream becomes byte-oriented (see
Upon successful completion, and return the next byte from the input
stream pointed to by stream for and If the stream is at end-of-file,
the end-of-file indicator for the stream is set and EOF is returned.
If a read error occurs, the error indicator for the stream is set, is
set to indicate the error and EOF is returned.
When the file corresponding to an open stream gets extended after the
end-of-file is reached, any subsequent calls to these functions will
succeed and the end-of-file indicator will remain set. However, in the
UNIX2003 standards environment (see standards(5)), these functions will
return EOF and the end-of-file indicator will still remain set.
Upon successful completion, and return the next word from the input
stream pointed to by stream. If the stream is at end-of-file, the end-
of-file indicator for the stream is set and and return EOF. If a read
error occurs, the error indicator for the stream is set, and and return
EOF and set to indicate the error.
and can be used to distinguish between an error condition and an end-
and fail if data needs to be read into the stream's buffer, and:
The flag is set for the file descriptor underlying
stream and the process would be delayed in the
The file descriptor underlying
stream is not a valid file descriptor open for
The read operation was terminated due to the receipt of a sig‐
and either no data was transferred or the imple‐
mentation does not report partial transfer for
A physical I/O error has occurred, or the process is a
member of a background process and is attempting
to read from its controlling terminal, and either
the process is ignoring or blocking the signal or
the process group of the process is orphaned.
Additional values may be set by the underlying function (see read(2)).
and are implemented both as library functions and macros. The macro
versions, which are used by default, are defined in To obtain the
library function either use a to remove the macro definition or, if
compiling in ANSI-C mode, enclose the function name in parenthesis or
use the function address. The following example illustrates each of
these methods :
If the integer value returned by or is stored into a character variable
then compared against the integer constant the comparison may never
succeed because sign-extension of a character on widening to integer is
The macro version of incorrectly treats a stream argument with side
effects. In particular, does not work sensibly. The function version
of or should be used instead.
Because of possible differences in word length and byte ordering, files
written using are machine-dependent, and may be unreadable by on a dif‐
If is defined before including the locked versions of the library func‐
tions for and are used by default.
is an obsolescent interface supported only for compatibility with
existing DCE applications. New multithreaded applications should use
SEE ALSOread(2), fclose(3S), ferror(3S), flockfile(3S), fopen(3S), fread(3S),
gets(3S), putc(3S), scanf(3S), orientation(5), standards(5),