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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 a null byte ('\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 terminating null byte ('\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 nonlocking 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

       C89, C99, POSIX.1-2001.  LSB deprecates gets().  POSIX.1-2008 marks gets() obsolescent.

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(2)  for  the file descriptor associated with the input stream; the results
       will be undefined and very probably not what you want.

SEE ALSO

       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)

COLOPHON

       This  page  is  part of release 3.35 of the Linux man-pages project.  A description of the
       project, and information about reporting bugs, can be found at  http://man7.org/linux/man-
       pages/.