fgetc, fgets, getc, getchar, gets, ungetc - input of charac-
ters and strings
int fgetc(FILE *stream));
char *fgets(char *s, int size, FILE *stream
int getc(FILE *stream));
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
getc() is equivalent to fgetc() except that it may be imple-
mented 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 per-
formed (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.
fgetc(), getc() and getchar() return the character read as
an unsigned char cast to an int or EOF on end of file or
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
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), fopen(3), scanf(3), puts(3), fseek(3),