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Diffstat (limited to 'newlib/libc/stdio/gets.c')
-rw-r--r-- | newlib/libc/stdio/gets.c | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/newlib/libc/stdio/gets.c b/newlib/libc/stdio/gets.c new file mode 100644 index 0000000..796100e --- /dev/null +++ b/newlib/libc/stdio/gets.c @@ -0,0 +1,102 @@ +/* + * Copyright (c) 1990 The Regents of the University of California. + * All rights reserved. + * + * Redistribution and use in source and binary forms are permitted + * provided that the above copyright notice and this paragraph are + * duplicated in all such forms and that any documentation, + * advertising materials, and other materials related to such + * distribution and use acknowledge that the software was developed + * by the University of California, Berkeley. The name of the + * University may not be used to endorse or promote products derived + * from this software without specific prior written permission. + * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR + * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. + */ + + +/* + +FUNCTION + <<gets>>---get character string (obsolete, use <<fgets>> instead) +INDEX + gets +INDEX + _gets_r + +ANSI_SYNOPSIS + #include <stdio.h> + + char *gets(char *<[buf]>); + + char *_gets_r(void *<[reent]>, char *<[buf]>); + +TRAD_SYNOPSIS + #include <stdio.h> + + char *gets(<[buf]>) + char *<[buf]>; + + char *_gets_r(<[reent]>, <[buf]>) + char *<[reent]>; + char *<[buf]>; + +DESCRIPTION + Reads characters from standard input until a newline is found. + The characters up to the newline are stored in <[buf]>. The + newline is discarded, and the buffer is terminated with a 0. + + This is a @emph{dangerous} function, as it has no way of checking + the amount of space available in <[buf]>. One of the attacks + used by the Internet Worm of 1988 used this to overrun a + buffer allocated on the stack of the finger daemon and + overwrite the return address, causing the daemon to execute + code downloaded into it over the connection. + + The alternate function <<_gets_r>> is a reentrant version. The extra + argument <[reent]> is a pointer to a reentrancy structure. + + +RETURNS + <<gets>> returns the buffer passed to it, with the data filled + in. If end of file occurs with some data already accumulated, + the data is returned with no other indication. If end of file + occurs with no data in the buffer, NULL is returned. + +Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>, +<<lseek>>, <<read>>, <<sbrk>>, <<write>>. +*/ + +#include <stdio.h> + +char * +_gets_r (ptr, buf) + struct _reent *ptr; + char *buf; +{ + register int c; + register char *s = buf; + + while ((c = _getchar_r (ptr)) != '\n') + if (c == EOF) + if (s == buf) + return NULL; + else + break; + else + *s++ = c; + *s = 0; + return buf; +} + +#ifndef _REENT_ONLY + +char * +gets (buf) + char *buf; +{ + return _gets_r (_REENT, buf); +} + +#endif |