/* @(#)fwrite.c 3.6 */ /*LINTLIBRARY*/ /* * This version writes directly to the buffer rather than looping on putc. * Ptr args aren't checked for NULL because the program would be a * catastrophic mess anyway. Better to abort than just to return NULL. * * This version does buffered writes larger than BUFSIZ directly, when * the buffer is empty. */ #include <stdio.h> #include "stdiom.h" #define MIN(x, y) (x < y ? x : y) extern char *memcpy(); int fwrite(ptr, size, count, iop) char *ptr; int size, count; register FILE *iop; { register unsigned nleft; register int n; register unsigned char *cptr, *bufend; if (size <= 0 || count <= 0 || _WRTCHK(iop)) return (0); bufend = _bufend(iop); nleft = count*size; /* if the file is unbuffered, or if the iop->ptr = iop->base, and there is > BUFSZ chars to write, we can do a direct write */ if (iop->_base >= iop->_ptr) { /*this covers the unbuffered case, too*/ if (((iop->_flag & _IONBF) != 0) || (nleft >= BUFSIZ)) { if ((n=write(fileno(iop),ptr,nleft)) != nleft) { iop->_flag |= _IOERR; n = (n >= 0) ? n : 0; } return n/size; } } /* Put characters in the buffer */ /* note that the meaning of n when just starting this loop is irrelevant. It is defined in the loop */ for (; ; ptr += n) { while ((n = bufend - (cptr = iop->_ptr)) <= 0) /* full buf */ if (_xflsbuf(iop) == EOF) return (count - (nleft + size - 1)/size); n = MIN(nleft, n); (void) memcpy((char *) cptr, ptr, n); iop->_cnt -= n; iop->_ptr += n; _BUFSYNC(iop); /* done; flush if linebuffered with a newline */ if ((nleft -= n) == 0) { if (iop->_flag & (_IOLBF | _IONBF)) { if ((iop->_flag & _IONBF) || (memchr(iop->_base, '\n',count * size) != NULL)) { (void) _xflsbuf(iop); } } return (count); } } }