/********************************************************************** * Copyright (c) Digital Equipment Corporation 1984, 1985, 1986. * * All Rights Reserved. * * Reference "/usr/src/COPYRIGHT" for applicable restrictions. * **********************************************************************/ /* * SCCSID: @(#)fgets.c 3.0 4/22/86 */ /* (System 5) fgets.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" #define MIN(x, y) (x < y ? x : y) extern int _filbuf(); extern char *memccpy(); char * fgets(ptr, size, iop) char *ptr; register int size; register FILE *iop; { char *p, *ptr0 = ptr; register int n; for (size--; size > 0; size -= n) { if (iop->_cnt <= 0) { /* empty buffer */ if (_filbuf(iop) == EOF) { if (ptr0 == ptr) return (NULL); break; /* no more data */ } iop->_ptr--; iop->_cnt++; } n = MIN(size, iop->_cnt); if ((p = memccpy(ptr, (char *) iop->_ptr, '\n', n)) != NULL) n = p - ptr; ptr += n; iop->_cnt -= n; iop->_ptr += n; _BUFSYNC(iop); if (p != NULL) break; /* found '\n' in buffer */ } *ptr = '\0'; return (ptr0); }