/* util.c
*
- * Copyright (c) 1991-2002, Larry Wall
+ * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999,
+ * 2000, 2001, 2002, 2003, by Larry Wall and others
*
* You may distribute under the terms of either the GNU General Public
* License or the Artistic License, as specified in the README file.
#include "perl.h"
#ifndef PERL_MICRO
-#if !defined(NSIG) || defined(M_UNIX) || defined(M_XENIX)
#include <signal.h>
-#endif
-
#ifndef SIG_ERR
# define SIG_ERR ((Sighandler_t) -1)
#endif
else if (PL_nomemok)
return Nullch;
else {
- PerlIO_puts(Perl_error_log,PL_no_mem) FLUSH;
+ /* Can't use PerlIO to write as it allocates memory */
+ PerlLIO_write(PerlIO_fileno(Perl_error_log),
+ PL_no_mem, strlen(PL_no_mem));
my_exit(1);
return Nullch;
}
else if (PL_nomemok)
return Nullch;
else {
- PerlIO_puts(Perl_error_log,PL_no_mem) FLUSH;
+ /* Can't use PerlIO to write as it allocates memory */
+ PerlLIO_write(PerlIO_fileno(Perl_error_log),
+ PL_no_mem, strlen(PL_no_mem));
my_exit(1);
return Nullch;
}
else if (PL_nomemok)
return Nullch;
else {
- PerlIO_puts(Perl_error_log,PL_no_mem) FLUSH;
+ /* Can't use PerlIO to write as it allocates memory */
+ PerlLIO_write(PerlIO_fileno(Perl_error_log),
+ PL_no_mem, strlen(PL_no_mem));
my_exit(1);
return Nullch;
}
I32 rarest = 0;
U32 frequency = 256;
- if (flags & FBMcf_TAIL)
+ if (flags & FBMcf_TAIL) {
+ MAGIC *mg = SvUTF8(sv) && SvMAGICAL(sv) ? mg_find(sv, PERL_MAGIC_utf8) : NULL;
sv_catpvn(sv, "\n", 1); /* Taken into account in fbm_instr() */
+ if (mg && mg->mg_len >= 0)
+ mg->mg_len++;
+ }
s = (U8*)SvPV_force(sv, len);
(void)SvUPGRADE(sv, SVt_PVBM);
if (len == 0) /* TAIL might be on a zero-length string. */
return sv;
}
+void
+Perl_write_to_stderr(pTHX_ const char* message, int msglen)
+{
+ IO *io;
+ MAGIC *mg;
+
+ if (PL_stderrgv && SvREFCNT(PL_stderrgv)
+ && (io = GvIO(PL_stderrgv))
+ && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar)))
+ {
+ dSP;
+ ENTER;
+ SAVETMPS;
+
+ save_re_context();
+ SAVESPTR(PL_stderrgv);
+ PL_stderrgv = Nullgv;
+
+ PUSHSTACKi(PERLSI_MAGIC);
+
+ PUSHMARK(SP);
+ EXTEND(SP,2);
+ PUSHs(SvTIED_obj((SV*)io, mg));
+ PUSHs(sv_2mortal(newSVpvn(message, msglen)));
+ PUTBACK;
+ call_method("PRINT", G_SCALAR);
+
+ POPSTACK;
+ FREETMPS;
+ LEAVE;
+ }
+ else {
+#ifdef USE_SFIO
+ /* SFIO can really mess with your errno */
+ int e = errno;
+#endif
+ PerlIO *serr = Perl_error_log;
+
+ PERL_WRITE_MSG_TO_CONSOLE(serr, message, msglen);
+ (void)PerlIO_flush(serr);
+#ifdef USE_SFIO
+ errno = e;
+#endif
+ }
+}
+
OP *
Perl_vdie(pTHX_ const char* pat, va_list *args)
{
CV *cv;
SV *msv;
STRLEN msglen;
+ I32 utf8 = 0;
DEBUG_S(PerlIO_printf(Perl_debug_log,
"%p: die: curstack = %p, mainstack = %p\n",
}
else
message = SvPV(msv,msglen);
+ utf8 = SvUTF8(msv);
}
else {
message = Nullch;
save_re_context();
if (message) {
msg = newSVpvn(message, msglen);
+ SvFLAGS(msg) |= utf8;
SvREADONLY_on(msg);
SAVEFREESV(msg);
}
}
PL_restartop = die_where(message, msglen);
+ SvFLAGS(ERRSV) |= utf8;
DEBUG_S(PerlIO_printf(Perl_debug_log,
"%p: die: restartop = %p, was_in_eval = %d, top_env = %p\n",
thr, PL_restartop, was_in_eval, PL_top_env));
CV *cv;
SV *msv;
STRLEN msglen;
+ I32 utf8 = 0;
if (pat) {
msv = vmess(pat, args);
}
else
message = SvPV(msv,msglen);
+ utf8 = SvUTF8(msv);
}
else {
message = Nullch;
save_re_context();
if (message) {
msg = newSVpvn(message, msglen);
+ SvFLAGS(msg) |= utf8;
SvREADONLY_on(msg);
SAVEFREESV(msg);
}
}
if (PL_in_eval) {
PL_restartop = die_where(message, msglen);
+ SvFLAGS(ERRSV) |= utf8;
JMPENV_JUMP(3);
}
else if (!message)
message = SvPVx(ERRSV, msglen);
- {
-#ifdef USE_SFIO
- /* SFIO can really mess with your errno */
- int e = errno;
-#endif
- PerlIO *serr = Perl_error_log;
-
- PERL_WRITE_MSG_TO_CONSOLE(serr, message, msglen);
- (void)PerlIO_flush(serr);
-#ifdef USE_SFIO
- errno = e;
-#endif
- }
+ write_to_stderr(message, msglen);
my_failure_exit();
}
CV *cv;
SV *msv;
STRLEN msglen;
- IO *io;
- MAGIC *mg;
+ I32 utf8 = 0;
msv = vmess(pat, args);
+ utf8 = SvUTF8(msv);
message = SvPV(msv, msglen);
if (PL_warnhook) {
ENTER;
save_re_context();
msg = newSVpvn(message, msglen);
+ SvFLAGS(msg) |= utf8;
SvREADONLY_on(msg);
SAVEFREESV(msg);
}
}
- /* if STDERR is tied, use it instead */
- if (PL_stderrgv && (io = GvIOp(PL_stderrgv))
- && (mg = SvTIED_mg((SV*)io, PERL_MAGIC_tiedscalar))) {
- dSP; ENTER;
- PUSHMARK(SP);
- XPUSHs(SvTIED_obj((SV*)io, mg));
- XPUSHs(sv_2mortal(newSVpvn(message, msglen)));
- PUTBACK;
- call_method("PRINT", G_SCALAR);
- LEAVE;
- return;
- }
-
- {
- PerlIO *serr = Perl_error_log;
-
- PERL_WRITE_MSG_TO_CONSOLE(serr, message, msglen);
- (void)PerlIO_flush(serr);
- }
+ write_to_stderr(message, msglen);
}
#if defined(PERL_IMPLICIT_CONTEXT)
CV *cv;
SV *msv;
STRLEN msglen;
+ I32 utf8 = 0;
msv = vmess(pat, args);
message = SvPV(msv, msglen);
+ utf8 = SvUTF8(msv);
if (ckDEAD(err)) {
if (PL_diehook) {
ENTER;
save_re_context();
msg = newSVpvn(message, msglen);
+ SvFLAGS(msg) |= utf8;
SvREADONLY_on(msg);
SAVEFREESV(msg);
}
if (PL_in_eval) {
PL_restartop = die_where(message, msglen);
+ SvFLAGS(ERRSV) |= utf8;
JMPENV_JUMP(3);
}
- {
- PerlIO *serr = Perl_error_log;
- PERL_WRITE_MSG_TO_CONSOLE(serr, message, msglen);
- (void)PerlIO_flush(serr);
- }
+ write_to_stderr(message, msglen);
my_failure_exit();
}
else {
ENTER;
save_re_context();
msg = newSVpvn(message, msglen);
+ SvFLAGS(msg) |= utf8;
SvREADONLY_on(msg);
SAVEFREESV(msg);
return;
}
}
- {
- PerlIO *serr = Perl_error_log;
- PERL_WRITE_MSG_TO_CONSOLE(serr, message, msglen);
- (void)PerlIO_flush(serr);
- }
+ write_to_stderr(message, msglen);
}
}
#endif /* WIN32 || NETWARE */
+#ifndef PERL_MICRO
I32
Perl_setenv_getix(pTHX_ char *nam)
{
} /* potential SEGV's */
return i;
}
+#endif /* !PERL_MICRO */
#endif /* !VMS && !EPOC*/
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
#ifdef SA_RESTART
-#if defined(PERL_OLD_SIGNALS)
- act.sa_flags |= SA_RESTART; /* SVR4, 4.3+BSD */
-#endif
+ if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
+ act.sa_flags |= SA_RESTART; /* SVR4, 4.3+BSD */
#endif
-#ifdef SA_NOCLDWAIT
+#if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
if (signo == SIGCHLD && handler == (Sighandler_t)SIG_IGN)
act.sa_flags |= SA_NOCLDWAIT;
#endif
sigemptyset(&act.sa_mask);
act.sa_flags = 0;
#ifdef SA_RESTART
-#if defined(PERL_OLD_SIGNALS)
- act.sa_flags |= SA_RESTART; /* SVR4, 4.3+BSD */
-#endif
+ if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG)
+ act.sa_flags |= SA_RESTART; /* SVR4, 4.3+BSD */
#endif
-#ifdef SA_NOCLDWAIT
+#if defined(SA_NOCLDWAIT) && !defined(BSDish) /* See [perl #18849] */
if (signo == SIGCHLD && handler == (Sighandler_t)SIG_IGN)
act.sa_flags |= SA_NOCLDWAIT;
#endif
}
/*
-=head1 SV Manipulation Functions
-
-=for apidoc scan_vstring
-
-Returns a pointer to the next character after the parsed
-vstring, as well as updating the passed in sv.
-
-Function must be called like
-
- sv = NEWSV(92,5);
- s = scan_vstring(s,sv);
-
-The sv should already be large enough to store the vstring
-passed in, for performance reasons.
-
-=cut
-*/
-
-char *
-Perl_scan_vstring(pTHX_ char *s, SV *sv)
-{
- char *pos = s;
- char *start = s;
- if (*pos == 'v') pos++; /* get past 'v' */
- while (isDIGIT(*pos) || *pos == '_')
- pos++;
- if (!isALPHA(*pos)) {
- UV rev;
- U8 tmpbuf[UTF8_MAXLEN+1];
- U8 *tmpend;
-
- if (*s == 'v') s++; /* get past 'v' */
-
- sv_setpvn(sv, "", 0);
-
- for (;;) {
- rev = 0;
- {
- /* this is atoi() that tolerates underscores */
- char *end = pos;
- UV mult = 1;
- while (--end >= s) {
- UV orev;
- if (*end == '_')
- continue;
- orev = rev;
- rev += (*end - '0') * mult;
- mult *= 10;
- if (orev > rev && ckWARN_d(WARN_OVERFLOW))
- Perl_warner(aTHX_ packWARN(WARN_OVERFLOW),
- "Integer overflow in decimal number");
- }
- }
-#ifdef EBCDIC
- if (rev > 0x7FFFFFFF)
- Perl_croak(aTHX "In EBCDIC the v-string components cannot exceed 2147483647");
-#endif
- /* Append native character for the rev point */
- tmpend = uvchr_to_utf8(tmpbuf, rev);
- sv_catpvn(sv, (const char*)tmpbuf, tmpend - tmpbuf);
- if (!UNI_IS_INVARIANT(NATIVE_TO_UNI(rev)))
- SvUTF8_on(sv);
- if (*pos == '.' && isDIGIT(pos[1]))
- s = ++pos;
- else {
- s = pos;
- break;
- }
- while (isDIGIT(*pos) || *pos == '_')
- pos++;
- }
- SvPOK_on(sv);
- sv_magic(sv,NULL,PERL_MAGIC_vstring,(const char*)start, pos-start);
- SvRMAGICAL_on(sv);
- }
- return s;
-}
-
-/*
=for apidoc scan_version
Returns a pointer to the next character after the parsed
Function must be called with an already existing SV like
- sv = NEWSV(92,0);
- s = scan_version(s,sv);
+ sv = newSV(0);
+ s = scan_version(s,SV *sv, bool qv);
Performs some preprocessing to the string to ensure that
it has the correct characteristics of a version. Flags the
object if it contains an underscore (which denotes this
-is a beta version).
+is a alpha version). The boolean qv denotes that the version
+should be interpreted as if it had multiple decimals, even if
+it doesn't.
=cut
*/
char *
-Perl_scan_version(pTHX_ char *s, SV *rv)
+Perl_scan_version(pTHX_ char *s, SV *rv, bool qv)
{
const char *start = s;
char *pos = s;
}
pos = s;
- if (*pos == 'v') pos++; /* get past 'v' */
+ if (*pos == 'v') {
+ pos++; /* get past 'v' */
+ qv = 1; /* force quoted version processing */
+ }
while (isDIGIT(*pos))
pos++;
if (!isALPHA(*pos)) {
I32 mult = 1;
I32 orev;
if ( s < pos && s > start && *(s-1) == '_' ) {
- mult *= -1; /* beta version */
+ mult *= -1; /* alpha version */
}
/* the following if() will only be true after the decimal
* point of a version originally created with a bare
* floating point number, i.e. not quoted in any way
*/
- if ( s > start+1 && saw_period == 1 && !saw_under ) {
+ if ( !qv && s > start+1 && saw_period == 1 && !saw_under ) {
mult = 100;
while ( s < end ) {
orev = rev;
rev += (*s - '0') * mult;
mult /= 10;
- if ( abs(orev) > abs(rev) )
+ if ( PERL_ABS(orev) > PERL_ABS(rev) )
Perl_croak(aTHX_ "Integer overflow in version");
s++;
}
orev = rev;
rev += (*end - '0') * mult;
mult *= 10;
- if ( abs(orev) > abs(rev) )
+ if ( PERL_ABS(orev) > PERL_ABS(rev) )
Perl_croak(aTHX_ "Integer overflow in version");
}
}
Perl_new_version(pTHX_ SV *ver)
{
SV *rv = newSV(0);
- char *version;
- if ( SvNOK(ver) ) /* may get too much accuracy */
- {
- char tbuf[64];
- sprintf(tbuf,"%.9"NVgf, SvNVX(ver));
- version = savepv(tbuf);
- }
#ifdef SvVOK
- else if ( SvVOK(ver) ) { /* already a v-string */
+ if ( SvVOK(ver) ) { /* already a v-string */
+ char *version;
MAGIC* mg = mg_find(ver,PERL_MAGIC_vstring);
version = savepvn( (const char*)mg->mg_ptr,mg->mg_len );
+ sv_setpv(rv,version);
+ Safefree(version);
}
+ else {
#endif
- else /* must be a string or something like a string */
- {
- version = (char *)SvPV(ver,PL_na);
+ sv_setsv(rv,ver); /* make a duplicate */
+#ifdef SvVOK
}
- version = scan_version(version,rv);
+#endif
+ upg_version(rv);
return rv;
}
SV *
Perl_upg_version(pTHX_ SV *ver)
{
- char *version = savepvn(SvPVX(ver),SvCUR(ver));
+ char *version;
+ bool qv = 0;
+
+ if ( SvNOK(ver) ) /* may get too much accuracy */
+ {
+ char tbuf[64];
+ sprintf(tbuf,"%.9"NVgf, SvNVX(ver));
+ version = savepv(tbuf);
+ }
#ifdef SvVOK
- if ( SvVOK(ver) ) { /* already a v-string */
+ else if ( SvVOK(ver) ) { /* already a v-string */
MAGIC* mg = mg_find(ver,PERL_MAGIC_vstring);
version = savepvn( (const char*)mg->mg_ptr,mg->mg_len );
+ qv = 1;
}
#endif
- version = scan_version(version,ver);
+ else /* must be a string or something like a string */
+ {
+ STRLEN n_a;
+ version = savepv(SvPV(ver,n_a));
+ }
+ (void)scan_version(version, ver, qv);
+ Safefree(version);
return ver;
}
Perl_vnumify(pTHX_ SV *vs)
{
I32 i, len, digit;
- SV *sv = NEWSV(92,0);
+ SV *sv = newSV(0);
if ( SvROK(vs) )
vs = SvRV(vs);
len = av_len((AV *)vs);
return sv;
}
digit = SvIVX(*av_fetch((AV *)vs, 0, 0));
- Perl_sv_setpvf(aTHX_ sv,"%d.",abs(digit));
+ Perl_sv_setpvf(aTHX_ sv,"%d.", PERL_ABS(digit));
for ( i = 1 ; i <= len ; i++ )
{
digit = SvIVX(*av_fetch((AV *)vs, i, 0));
- Perl_sv_catpvf(aTHX_ sv,"%03d",abs(digit));
+ Perl_sv_catpvf(aTHX_ sv,"%03d", PERL_ABS(digit));
}
if ( len == 0 )
Perl_sv_catpv(aTHX_ sv,"000");
Perl_vstringify(pTHX_ SV *vs)
{
I32 i, len, digit;
- SV *sv = NEWSV(92,0);
+ SV *sv = newSV(0);
if ( SvROK(vs) )
vs = SvRV(vs);
len = av_len((AV *)vs);
else
Perl_sv_catpvf(aTHX_ sv,".%"IVdf,(IV)digit);
}
- if ( len == 0 )
- Perl_sv_catpv(aTHX_ sv,".0");
+
+ if ( len <= 2 ) { /* short version, must be at least three */
+ for ( len = 2 - len; len != 0; len-- )
+ Perl_sv_catpv(aTHX_ sv,".0");
+ }
+
return sv;
}
{
I32 left = SvIV(*av_fetch((AV *)lsv,i,0));
I32 right = SvIV(*av_fetch((AV *)rsv,i,0));
- bool lbeta = left < 0 ? 1 : 0;
- bool rbeta = right < 0 ? 1 : 0;
+ bool lalpha = left < 0 ? 1 : 0;
+ bool ralpha = right < 0 ? 1 : 0;
left = abs(left);
right = abs(right);
- if ( left < right || (left == right && lbeta && !rbeta) )
+ if ( left < right || (left == right && lalpha && !ralpha) )
retval = -1;
- if ( left > right || (left == right && rbeta && !lbeta) )
+ if ( left > right || (left == right && ralpha && !lalpha) )
retval = +1;
i++;
}
- if ( l != r && retval == 0 ) /* possible match except for trailing 0 */
+ if ( l != r && retval == 0 ) /* possible match except for trailing 0's */
{
- if ( !( l < r && r-l == 1 && SvIV(*av_fetch((AV *)rsv,r,0)) == 0 ) &&
- !( l-r == 1 && SvIV(*av_fetch((AV *)lsv,l,0)) == 0 ) )
+ if ( l < r )
+ {
+ while ( i <= r && retval == 0 )
+ {
+ if ( SvIV(*av_fetch((AV *)rsv,i,0)) != 0 )
+ retval = -1; /* not a match after all */
+ i++;
+ }
+ }
+ else
{
- retval = l < r ? -1 : +1; /* not a match after all */
+ while ( i <= l && retval == 0 )
+ {
+ if ( SvIV(*av_fetch((AV *)lsv,i,0)) != 0 )
+ retval = +1; /* not a match after all */
+ i++;
+ }
}
}
return retval;
{
}
+U32
+Perl_parse_unicode_opts(pTHX_ char **popt)
+{
+ char *p = *popt;
+ U32 opt = 0;
+
+ if (*p) {
+ if (isDIGIT(*p)) {
+ opt = (U32) atoi(p);
+ while (isDIGIT(*p)) p++;
+ if (*p && *p != '\n' && *p != '\r')
+ Perl_croak(aTHX_ "Unknown Unicode option letter '%c'", *p);
+ }
+ else {
+ for (; *p; p++) {
+ switch (*p) {
+ case PERL_UNICODE_STDIN:
+ opt |= PERL_UNICODE_STDIN_FLAG; break;
+ case PERL_UNICODE_STDOUT:
+ opt |= PERL_UNICODE_STDOUT_FLAG; break;
+ case PERL_UNICODE_STDERR:
+ opt |= PERL_UNICODE_STDERR_FLAG; break;
+ case PERL_UNICODE_STD:
+ opt |= PERL_UNICODE_STD_FLAG; break;
+ case PERL_UNICODE_IN:
+ opt |= PERL_UNICODE_IN_FLAG; break;
+ case PERL_UNICODE_OUT:
+ opt |= PERL_UNICODE_OUT_FLAG; break;
+ case PERL_UNICODE_INOUT:
+ opt |= PERL_UNICODE_INOUT_FLAG; break;
+ case PERL_UNICODE_LOCALE:
+ opt |= PERL_UNICODE_LOCALE_FLAG; break;
+ case PERL_UNICODE_ARGV:
+ opt |= PERL_UNICODE_ARGV_FLAG; break;
+ default:
+ if (*p != '\n' && *p != '\r')
+ Perl_croak(aTHX_
+ "Unknown Unicode option letter '%c'", *p);
+ }
+ }
+ }
+ }
+ else
+ opt = PERL_UNICODE_DEFAULT_FLAGS;
+
+ if (opt & ~PERL_UNICODE_ALL_FLAGS)
+ Perl_croak(aTHX_ "Unknown Unicode option value %"UVuf,
+ (UV) (opt & ~PERL_UNICODE_ALL_FLAGS));
+
+ *popt = p;
+
+ return opt;
+}
+
+U32
+Perl_seed(pTHX)
+{
+ /*
+ * This is really just a quick hack which grabs various garbage
+ * values. It really should be a real hash algorithm which
+ * spreads the effect of every input bit onto every output bit,
+ * if someone who knows about such things would bother to write it.
+ * Might be a good idea to add that function to CORE as well.
+ * No numbers below come from careful analysis or anything here,
+ * except they are primes and SEED_C1 > 1E6 to get a full-width
+ * value from (tv_sec * SEED_C1 + tv_usec). The multipliers should
+ * probably be bigger too.
+ */
+#if RANDBITS > 16
+# define SEED_C1 1000003
+#define SEED_C4 73819
+#else
+# define SEED_C1 25747
+#define SEED_C4 20639
+#endif
+#define SEED_C2 3
+#define SEED_C3 269
+#define SEED_C5 26107
+
+#ifndef PERL_NO_DEV_RANDOM
+ int fd;
+#endif
+ U32 u;
+#ifdef VMS
+# include <starlet.h>
+ /* when[] = (low 32 bits, high 32 bits) of time since epoch
+ * in 100-ns units, typically incremented ever 10 ms. */
+ unsigned int when[2];
+#else
+# ifdef HAS_GETTIMEOFDAY
+ struct timeval when;
+# else
+ Time_t when;
+# endif
+#endif
+
+/* This test is an escape hatch, this symbol isn't set by Configure. */
+#ifndef PERL_NO_DEV_RANDOM
+#ifndef PERL_RANDOM_DEVICE
+ /* /dev/random isn't used by default because reads from it will block
+ * if there isn't enough entropy available. You can compile with
+ * PERL_RANDOM_DEVICE to it if you'd prefer Perl to block until there
+ * is enough real entropy to fill the seed. */
+# define PERL_RANDOM_DEVICE "/dev/urandom"
+#endif
+ fd = PerlLIO_open(PERL_RANDOM_DEVICE, 0);
+ if (fd != -1) {
+ if (PerlLIO_read(fd, &u, sizeof u) != sizeof u)
+ u = 0;
+ PerlLIO_close(fd);
+ if (u)
+ return u;
+ }
+#endif
+
+#ifdef VMS
+ _ckvmssts(sys$gettim(when));
+ u = (U32)SEED_C1 * when[0] + (U32)SEED_C2 * when[1];
+#else
+# ifdef HAS_GETTIMEOFDAY
+ PerlProc_gettimeofday(&when,NULL);
+ u = (U32)SEED_C1 * when.tv_sec + (U32)SEED_C2 * when.tv_usec;
+# else
+ (void)time(&when);
+ u = (U32)SEED_C1 * when;
+# endif
+#endif
+ u += SEED_C3 * (U32)PerlProc_getpid();
+ u += SEED_C4 * (U32)PTR2UV(PL_stack_sp);
+#ifndef PLAN9 /* XXX Plan9 assembler chokes on this; fix needed */
+ u += SEED_C5 * (U32)PTR2UV(&when);
+#endif
+ return u;
+}
+
+UV
+Perl_get_hash_seed(pTHX)
+{
+ char *s = PerlEnv_getenv("PERL_HASH_SEED");
+ UV myseed = 0;
+
+ if (s)
+ while (isSPACE(*s)) s++;
+ if (s && isDIGIT(*s))
+ myseed = (UV)Atoul(s);
+ else
+#ifdef USE_HASH_SEED_EXPLICIT
+ if (s)
+#endif
+ {
+ /* Compute a random seed */
+ (void)seedDrand01((Rand_seed_t)seed());
+ myseed = (UV)(Drand01() * (NV)UV_MAX);
+#if RANDBITS < (UVSIZE * 8)
+ /* Since there are not enough randbits to to reach all
+ * the bits of a UV, the low bits might need extra
+ * help. Sum in another random number that will
+ * fill in the low bits. */
+ myseed +=
+ (UV)(Drand01() * (NV)((1 << ((UVSIZE * 8 - RANDBITS))) - 1));
+#endif /* RANDBITS < (UVSIZE * 8) */
+ if (myseed == 0) { /* Superparanoia. */
+ myseed = (UV)(Drand01() * (NV)UV_MAX); /* One more chance. */
+ if (myseed == 0)
+ Perl_croak(aTHX_ "Your random numbers are not that random");
+ }
+ }
+ PL_rehash_seed_set = TRUE;
+
+ return myseed;
+}