60 lines
1.2 KiB
C
60 lines
1.2 KiB
C
#if !defined(lint) && defined(SCCSIDS)
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static char sccsid[] = "@(#)fgets.c 1.1 94/10/31 SMI"; /* from S5R2 3.3 */
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#endif
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/*LINTLIBRARY*/
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/*
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* This version reads directly from the buffer rather than looping on getc.
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* Ptr args aren't checked for NULL because the program would be a
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* catastrophic mess anyway. Better to abort than just to return NULL.
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*/
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#include <stdio.h>
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#include "stdiom.h"
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#include <errno.h>
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#define MIN(x, y) (x < y ? x : y)
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extern int _filbuf();
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extern char *memccpy();
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char *
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fgets(ptr, size, iop)
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char *ptr;
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register int size;
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register FILE *iop;
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{
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char *p, *ptr0 = ptr;
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register int n;
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if ( !(iop->_flag & (_IOREAD|_IORW)) ) {
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iop->_flag |= _IOERR;
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#ifdef POSIX
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errno = EBADF;
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#endif
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return (NULL);
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}
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for (size--; size > 0; size -= n) {
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if (iop->_cnt <= 0) { /* empty buffer */
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if (_filbuf(iop) == EOF) {
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if (ptr0 == ptr)
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return (NULL);
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break; /* no more data */
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}
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iop->_ptr--;
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iop->_cnt++;
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}
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n = MIN(size, iop->_cnt);
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if ((p = memccpy(ptr, (char *) iop->_ptr, '\n', n)) != NULL)
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n = p - ptr;
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ptr += n;
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iop->_cnt -= n;
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iop->_ptr += n;
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_BUFSYNC(iop);
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if (p != NULL)
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break; /* found '\n' in buffer */
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}
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*ptr = '\0';
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return (ptr0);
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}
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