getchar_unlocked(3) - NetBSD Manual Pages

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GETC(3)                 NetBSD Library Functions Manual                GETC(3)


NAME
fgetc, getc, getchar, getc_unlocked, getchar_unlocked, getw -- get next character or word from input stream
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <stdio.h> int fgetc(FILE *stream); int getc(FILE *stream); int getchar(); int getc_unlocked(FILE *stream); int getchar_unlocked(); int getw(FILE *stream);
DESCRIPTION
The fgetc() function obtains the next input character (if present) from the stream pointed at by stream, or the next character pushed back on the stream via ungetc(3). The getc() function acts essentially identically to fgetc(), but is a macro that expands in-line. The getchar() function is equivalent to: getc with the argument stdin. The getc_unlocked() and getchar_unlocked() functions provide functional- ity identical to that of getc() and getchar(), respectively, but do not perform implicit locking of the streams they operate on. In multi- threaded programs they may be used only within a scope in which the stream has been successfully locked by the calling thread using either flockfile(3) or ftrylockfile(3), and may later be released using funlockfile(3). The getw() function obtains the next int (if present) from the stream pointed at by stream.
RETURN VALUES
If successful, these routines return the next requested object from the stream. If the stream is at end-of-file or a read error occurs, the rou- tines return EOF. The routines feof(3) and ferror(3) must be used to distinguish between end-of-file and error. If an error occurs, the global variable errno is set to indicate the error. The end-of-file con- dition is remembered, even on a terminal, and all subsequent attempts to read will return EOF until the condition is cleared with clearerr(3).
SEE ALSO
ferror(3), flockfile(3), fopen(3), fread(3), ftrylockfile(3), funlockfile(3), putc(3), ungetc(3)
STANDARDS
The fgetc(), getc() and getchar() functions conform to ANSI X3.159-1989 (``ANSI C89''). The getc_unlocked() and getchar_unlocked() functions conform to ISO/IEC 9945-1:1996 (``POSIX.1'').
HISTORY
The getc() and getw() functions appeared in Version 1 AT&T UNIX.
BUGS
Since EOF is a valid integer value, feof(3) and ferror(3) must be used to check for failure after calling getw(). The size and byte order of an int varies from one machine to another, and getw() is not recommended for portable applications. NetBSD 10.99 September 2, 2019 NetBSD 10.99
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