getchar

GETS(3)			  Linux Programmer’s Manual		      GETS(3)



NAME
       fgetc,  fgets,  getc,  getchar, gets, ungetc - input of characters and
       strings

SYNOPSIS
       #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);

DESCRIPTION
       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).

RETURN VALUE
       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.

CONFORMING TO
       ANSI - C, POSIX.1.  LSB deprecates gets().

BUGS
       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 asso-
       ciated  with  the input stream; the results will be undefined and very
       probably not what you want.

SEE ALSO
       read(2), write(2), ferror(3), fopen(3), fread(3),  fseek(3),  puts(3),
       scanf(3), unlocked_stdio(3)



GNU				  1993-04-04			      GETS(3)