/********************************************************************** * Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. * * All Rights Reserved. * * Reference "/usr/src/COPYRIGHT" for applicable restrictions. * **********************************************************************/ /* * SCCSID: @(#)gets.c 3.0 4/22/86 */ /* (System 5) gets.c 3.3 */ /*LINTLIBRARY*/ /* * This version reads directly from the buffer rather than looping on getc. * Ptr args aren't checked for NULL because the program would be a * catastrophic mess anyway. Better to abort than just to return NULL. */ #include <stdio.h> #include "stdiom.h" extern int _filbuf(); extern _bufsync(); extern char *memccpy(); char * gets(ptr) char *ptr; { char *p, *ptr0 = ptr; register int n; for ( ; ; ) { if (stdin->_cnt <= 0) { /* empty buffer */ if (_filbuf(stdin) == EOF) { if (ptr0 == ptr) return (NULL); break; /* no more data */ } stdin->_ptr--; stdin->_cnt++; } n = stdin->_cnt; if ((p = memccpy(ptr, (char *) stdin->_ptr, '\n', n)) != NULL) n = p - ptr; ptr += n; stdin->_cnt -= n; stdin->_ptr += n; _BUFSYNC(stdin); if (p != NULL) { /* found '\n' in buffer */ ptr--; /* step back over '\n' */ break; } } *ptr = '\0'; return (ptr0); }