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OLDCRTL.C
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1993-03-16
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/* SCCS Id: @(#)oldcrtl.c 3.0 90/05/24
/* Pat Rankin May'90 */
/* VMS NetHack support, not needed for vms 4.6,4.7,or 5.x. */
#ifdef VERYOLD_VMS
/*
* The following routines are used by NetHack but were not available
* from the C Run-Time Library (VAXCRTL) prior to VMS V4.6.
*
* atexit, memcmp, memcpy, qsort, rename, vprintf, vsprintf
*
* Most of them are implemented here, but others will have to be worked
* around in another fashion [such as '#define USE_OLDARGS' (even though
* <varargs.h> is available) to avoid the need for vprintf & vsprintf].
*
*/
#define REG register
#ifndef SUPPRESS_MEM_FUNCS
/* note: hand optimized for VAX (hardware pre-decrement & post-increment) */
/* void *memset(void *, int, size_t) -- fill chunk of memory.
*/
char *memset( dst, fil, cnt )
REG char *dst;
REG char fil;
REG int cnt;
{
char *dst_p = dst;
while ( --cnt >= 0 )
*dst++ = fil;
return dst_p;
}
/* void *memcpy(void *, const void *, size_t) -- copy chunk of memory.
*/
char *memcpy( dst, src, cnt ) /*[functionally equivalent to memmove()]*/
REG char *dst;
REG char *src;
REG int cnt;
{
char *dst_p = dst;
if ( src == dst || cnt <= 0 ) {
; /* do nothing */
} else if ( dst < src || dst >= src + cnt ) {
while ( --cnt >= 0 )
*dst++ = *src++;
} else { /* work backwards */
dst += cnt, src += cnt;
while ( --cnt >= 0 )
*--dst = *--src;
}
return dst_p;
}
/* void *memchr(const void *, int, size_t) -- search for a byte.
*/
char *memchr( buf, byt, len )
REG char *buf;
REG char byt;
REG int len;
{
while ( --len >= 0 )
if ( *buf++ == byt ) /* found */
return --buf;
return (char *)0; /* not found */
}
/* int memcmp(const void *, const void *, size_t) -- compare two chunks.
*/
int memcmp( buf1, buf2, len )
REG char *buf1;
REG char *buf2;
REG int len;
{
while ( --len >= 0 )
if ( *buf1++ != *buf2++ )
return (*--buf1 - *--buf2);
return 0; /* buffers matched */
}
#endif /*!SUPPRESS_MEM_FUNCS*/
#ifndef SUPPRESS_ATEXIT
/* int atexit(void (*)(void)) -- register an exit handler.
*/
#define MAX_EXIT_FUNCS 32 /* arbitrary (32 matches VAX C v3.x docs) */
struct _ex_hndlr { long reserved, (*routine)(), arg_count, *arg1_addr; };
static int ex_cnt = 0; /* number of handlers registered so far */
static struct { long dummy_arg; struct _ex_hndlr handler; /*(black box)*/
} ex_data[MAX_EXIT_FUNCS]; /* static handler data */
int atexit( function )
int (*function)(); /* note: actually gets called with 1 arg */
{
if ( ex_cnt < MAX_EXIT_FUNCS ) {
ex_data[ex_cnt].dummy_arg = 0; /* ultimately receives exit reason */
ex_data[ex_cnt].handler.reserved = 0;
ex_data[ex_cnt].handler.routine = function;
ex_data[ex_cnt].handler.arg_count = 1; /*(required)*/
ex_data[ex_cnt].handler.arg1_addr = &ex_data[ex_cnt].dummy_arg;
SYS$DCLEXH( &ex_data[ex_cnt].handler); /* declare exit handler */
return ++ex_cnt; /*(non-zero)*/
} else
return 0;
}
#endif /*!SUPPRESS_ATEXIT*/
#ifndef SUPPRESS_RENAME
/* int rename(const char *, const char *) -- rename a file (on same device).
*/
#ifndef EVMSERR
#include <errno.h>
#define C$$TRANSLATE(status) (errno = EVMSERR, vaxc$errno = (status))
#endif
int rename( old_name, new_name )
char *old_name;
char *new_name;
{
struct _dsc { int len; char *adr; } old_dsc, new_dsc;
unsigned long status, LIB$RENAME_FILE();
/* put strings into descriptors and call run-time library routine */
old_dsc.len = strlen( old_dsc.adr = old_name );
new_dsc.len = strlen( new_dsc.adr = new_name );
status = LIB$RENAME_FILE( &old_dsc, &new_dsc); /* omit optional args */
if ( !(status & 1) ) { /* even => failure */
C$$TRANSLATE(status);
return -1;
} else /* odd => success */
return 0;
}
#endif /*!SUPPRESS_RENAME*/
#ifndef SUPPRESS_QSORT
/* void qsort(void *, size_t, size_t, int (*)()) -- sort arbitrary collection.
*/
void qsort( base, count, size, compare )
char *base;
int count;
REG int size;
int (*compare)();
{
REG int i, cmp;
REG char *next, *prev, *tmp = 0;
char wrk_buf[512], *malloc(); /* assume no alloca() available */
/* just use a shuffle sort (tradeoff between efficiency & simplicity) */
/* [Optimal if already sorted; worst case when initially reversed.] */
for ( next = base, i = 1; i < count; i++ ) {
prev = next, next += size; /* increment front pointer */
if ( (cmp = (*compare)( next, prev)) < 0 ) {
/* found element out of order; move other(s) up then re-insert it */
if ( !tmp ) tmp = (size > sizeof wrk_buf ? malloc(size) : wrk_buf);
memcpy( tmp, next, size); /* save smaller element */
while ( cmp < 0 ) {
memcpy( prev + size, prev, size); /* move larger elem. up */
prev -= size; /* decrement back pointer */
cmp = (prev >= base ? (*compare)( tmp, prev) : 0);
}
memcpy( prev + size, tmp, size); /* restore small element */
}
}
if ( tmp != 0 && tmp != wrk_buf ) free(tmp);
return;
}
#endif /*!SUPPRESS_QSORT*/
#endif /*VERYOLD_VMS*/