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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 '\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

       C89,  C99,  POSIX.1-2001.  LSB deprecates gets().  POSIX.1-2008 removes
       the specification of 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(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 3.21 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/.