Originální popis anglicky:
fgetc, fgets, getc, getchar, gets, ungetc - input of characters and strings
Návod, kniha: Linux Programmer's Manual
#include <stdio.h>
int fgetc(FILE *stream);
char *fgets(char *s, int size, FILE *stream);
int getc(FILE *stream);
int getchar(void);
char *gets(char *s);
int ungetc(int c, FILE *stream);
fgetc() reads the next character from
stream and returns it as an
unsigned char cast to an
int, or
EOF on end of file or
error.
getc() is equivalent to
fgetc() except that it may be implemented
as a macro which evaluates
stream more than once.
getchar() is equivalent to
getc(stdin).
gets() reads a line from
stdin into the buffer pointed to by
s until either a terminating newline or
EOF, which it replaces
with
'\0'. No check for buffer overrun is performed (see
BUGS
below).
fgets() reads in at most one less than
size characters from
stream and stores them into the buffer pointed to by
s. Reading
stops after an
EOF or a newline. If a newline is read, it is stored
into the buffer. A
'\0' is stored after the last character in the
buffer.
ungetc() pushes
c back to
stream, cast to
unsigned
char, where it is available for subsequent read operations. Pushed - back
characters will be returned in reverse order; only one pushback is guaranteed.
Calls to the functions described here can be mixed with each other and with
calls to other input functions from the
stdio library for the same
input stream.
For non-locking counterparts, see
unlocked_stdio(3).
fgetc(),
getc() and
getchar() return the character read as
an
unsigned char cast to an
int or
EOF on end of file or
error.
gets() and
fgets() return
s on success, and
NULL on
error or when end of file occurs while no characters have been read.
ungetc() returns
c on success, or
EOF on error.
ANSI - C, POSIX.1. LSB deprecates
gets().
Never use
gets(). Because it is impossible to tell without knowing the
data in advance how many characters
gets() will read, and because
gets() will continue to store characters past the end of the buffer, it
is extremely dangerous to use. It has been used to break computer security.
Use
fgets() instead.
It is not advisable to mix calls to input functions from the
stdio
library with low - level calls to
read() for the file descriptor
associated with the input stream; the results will be undefined and very
probably not what you want.
read(2),
write(2),
ferror(3),
fopen(3),
fread(3),
fseek(3),
puts(3),
scanf(3),
unlocked_stdio(3)
