NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | CONFORMING TO | BUGS | SEE ALSO | COLOPHON
GETS(3) Linux Programmer's Manual GETS(3)
fgetc, fgets, getc, getchar, gets, ungetc - input of characters and strings
#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.
C89, C99, POSIX.1-2001. LSB deprecates gets(). POSIX.1-2008 removes the
specification of 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(2) 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), fgetwc(3), fgetws(3), fopen(3), fread(3),
fseek(3), getline(3), getwchar(3), puts(3), scanf(3), ungetwc(3),
unlocked_stdio(3)
This page is part of release 3.23 of the Linux man-pages project. A
description of the project, and information about reporting bugs, can be found
at http://www.kernel.org/doc/man-pages/.
GNU 2008-08-06 GETS(3)