NG4R3P

Linux 4gvps.4gvps.com 3.10.0-1127.18.2.vz7.163.46 #1 SMP Fri Nov 20 21:47:55 MSK 2020 x86_64
SOFT : Apache PHP : 7.4.33
/usr/share/perl5/pod/

38.135.39.45

[ NAME ]	[ SIZE ]	[ PERM ]	[ DATE ]	[ ACT ]
+FILE +DIR
a2p.pod	5.962 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl.pod	15.429 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5004delta.pod	54.921 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5005delta.pod	33.48 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5100delta.pod	53.413 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5101delta.pod	42.858 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5120delta.pod	87.193 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5121delta.pod	9.905 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5122delta.pod	9.378 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5123delta.pod	4.004 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5124delta.pod	3.586 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5140delta.pod	140.941 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5141delta.pod	7.779 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5142delta.pod	6.73 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5143delta.pod	7.578 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5160delta.pod	130.52 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5161delta.pod	5.998 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5162delta.pod	3.51 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl5163delta.pod	3.985 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl561delta.pod	121.786 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl56delta.pod	104.685 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl581delta.pod	37.168 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl582delta.pod	4.365 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl583delta.pod	6.187 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl584delta.pod	7.19 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl585delta.pod	5.751 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl586delta.pod	4.542 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl587delta.pod	8.161 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl588delta.pod	24.68 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl589delta.pod	52.637 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perl58delta.pod	112.215 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlaix.pod	18.768 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlamiga.pod	6.869 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlapi.pod	315.465 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlapio.pod	18.878 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlartistic.pod	6.846 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbeos.pod	2.867 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbook.pod	7.192 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlboot.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbot.pod	0.178 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlbs2000.pod	7.733 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcall.pod	54.026 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlce.pod	8.723 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcheat.pod	4.395 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlclib.pod	7.504 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcn.pod	4.815 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcommunity.pod	6.293 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlcygwin.pod	27.17 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldata.pod	36.331 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldbmfilter.pod	4.863 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebguts.pod	36.789 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebtut.pod	20.786 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldebug.pod	38.151 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldelta.pod	3.985 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldgux.pod	2.754 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldiag.pod	207.818 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldos.pod	10.275 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldsc.pod	24.837 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perldtrace.pod	6.209 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlebcdic.pod	67.605 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlembed.pod	35.209 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlepoc.pod	3.572 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlexperiment.pod	4.843 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq.pod	22.007 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq1.pod	13.519 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq2.pod	9.278 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq3.pod	37.464 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq4.pod	87.393 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq5.pod	54.113 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq6.pod	38.664 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq7.pod	36.352 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq8.pod	48.279 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfaq9.pod	14.709 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfork.pod	12.782 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlform.pod	16.287 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfreebsd.pod	1.554 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlfunc.pod	338.432 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlgit.pod	29.755 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlglossary.pod	110.655 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlgpl.pod	13.537 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlguts.pod	111.664 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhack.pod	35.03 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhacktips.pod	45.498 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhacktut.pod	6.068 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhaiku.pod	1.469 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhist.pod	43.319 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhpux.pod	28.065 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlhurd.pod	1.94 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlintern.pod	42.532 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlinterp.pod	30.002 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlintro.pod	22.085 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perliol.pod	33.027 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlipc.pod	70.165 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlirix.pod	4.291 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perljp.pod	7.572 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlko.pod	7.521 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllexwarn.pod	14.612 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllinux.pod	1.453 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllocale.pod	51.435 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perllol.pod	10.935 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmacos.pod	0.978 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmacosx.pod	10.399 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmod.pod	24.041 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodinstall.pod	12.412 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodlib.pod	78.491 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmodstyle.pod	20.757 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmpeix.pod	14.236 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlmroapi.pod	3.128 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnetware.pod	6.348 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnewmod.pod	10.952 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlnumber.pod	8.156 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlobj.pod	33.653 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlootut.pod	25.604 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlop.pod	121.731 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlopenbsd.pod	1.176 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlopentut.pod	37.533 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos2.pod	90.533 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos390.pod	15.2 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlos400.pod	4.513 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpacktut.pod	49.834 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlperf.pod	50.048 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlplan9.pod	5.005 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpod.pod	21.27 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpodspec.pod	66.203 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpolicy.pod	19.726 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlport.pod	82.635 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlpragma.pod	5.105 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlqnx.pod	4.145 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlre.pod	100.761 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreapi.pod	25.168 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrebackslash.pod	25.644 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrecharclass.pod	34.188 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlref.pod	28.319 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreftut.pod	18.232 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreguts.pod	35.995 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrequick.pod	17.499 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlreref.pod	14.19 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlretut.pod	115.128 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlriscos.pod	1.493 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlrun.pod	49.575 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsec.pod	22.768 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsolaris.pod	28.63 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsource.pod	6.194 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlstyle.pod	8.416 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsub.pod	55.153 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsymbian.pod	15.439 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlsyn.pod	41.044 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlthrtut.pod	45.407 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltie.pod	37.02 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltoc.pod	638.995 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltodo.pod	0.354 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltooc.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltoot.pod	0.179 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltrap.pod	40.281 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltru64.pod	7.552 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perltw.pod	5.151 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunicode.pod	70.891 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunifaq.pod	13.314 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluniintro.pod	35.443 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluniprops.pod	229.736 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlunitut.pod	7.756 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlutil.pod	9.679 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perluts.pod	3.105 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvar.pod	69.188 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvmesa.pod	3.881 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvms.pod	51.333 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlvos.pod	5.823 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlwin32.pod	34.581 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxs.pod	71.663 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxstut.pod	48.517 KB	-rw-r--r--	2023-10-25 12:41	R E G D
perlxstypemap.pod	22.966 KB	-rw-r--r--	2023-10-25 12:41	R E G D
REQUEST EXIT

=head1 NAME perlapio - perl's IO abstraction interface. =head1 SYNOPSIS #define PERLIO_NOT_STDIO 0 /* For co-existence with stdio only */ #include /* Usually via #include */ PerlIO *PerlIO_stdin(void); PerlIO *PerlIO_stdout(void); PerlIO *PerlIO_stderr(void); PerlIO *PerlIO_open(const char *path,const char *mode); PerlIO *PerlIO_fdopen(int fd, const char *mode); PerlIO *PerlIO_reopen(const char *path, const char *mode, PerlIO *old); /* deprecated */ int PerlIO_close(PerlIO *f); int PerlIO_stdoutf(const char *fmt,...) int PerlIO_puts(PerlIO *f,const char *string); int PerlIO_putc(PerlIO *f,int ch); int PerlIO_write(PerlIO *f,const void *buf,size_t numbytes); int PerlIO_printf(PerlIO *f, const char *fmt,...); int PerlIO_vprintf(PerlIO *f, const char *fmt, va_list args); int PerlIO_flush(PerlIO *f); int PerlIO_eof(PerlIO *f); int PerlIO_error(PerlIO *f); void PerlIO_clearerr(PerlIO *f); int PerlIO_getc(PerlIO *d); int PerlIO_ungetc(PerlIO *f,int ch); int PerlIO_read(PerlIO *f, void *buf, size_t numbytes); int PerlIO_fileno(PerlIO *f); void PerlIO_setlinebuf(PerlIO *f); Off_t PerlIO_tell(PerlIO *f); int PerlIO_seek(PerlIO *f, Off_t offset, int whence); void PerlIO_rewind(PerlIO *f); int PerlIO_getpos(PerlIO *f, SV *save); /* prototype changed */ int PerlIO_setpos(PerlIO *f, SV *saved); /* prototype changed */ int PerlIO_fast_gets(PerlIO *f); int PerlIO_has_cntptr(PerlIO *f); int PerlIO_get_cnt(PerlIO *f); char *PerlIO_get_ptr(PerlIO *f); void PerlIO_set_ptrcnt(PerlIO *f, char *ptr, int count); int PerlIO_canset_cnt(PerlIO *f); /* deprecated */ void PerlIO_set_cnt(PerlIO *f, int count); /* deprecated */ int PerlIO_has_base(PerlIO *f); char *PerlIO_get_base(PerlIO *f); int PerlIO_get_bufsiz(PerlIO *f); PerlIO *PerlIO_importFILE(FILE *stdio, const char *mode); FILE *PerlIO_exportFILE(PerlIO *f, int flags); FILE *PerlIO_findFILE(PerlIO *f); void PerlIO_releaseFILE(PerlIO *f,FILE *stdio); int PerlIO_apply_layers(PerlIO *f, const char *mode, const char *layers); int PerlIO_binmode(PerlIO *f, int ptype, int imode, const char *layers); void PerlIO_debug(const char *fmt,...) =head1 DESCRIPTION Perl's source code, and extensions that want maximum portability, should use the above functions instead of those defined in ANSI C's I. The perl headers (in particular "perlio.h") will C<#define> them to the I/O mechanism selected at Configure time. The functions are modeled on those in I, but parameter order has been "tidied up a little". C takes the place of FILE *. Like FILE * it should be treated as opaque (it is probably safe to assume it is a pointer to something). There are currently three implementations: =over 4 =item 1. USE_STDIO All above are #define'd to stdio functions or are trivial wrapper functions which call stdio. In this case I PerlIO * is a FILE *. This has been the default implementation since the abstraction was introduced in perl5.003_02. =item 2. USE_SFIO A "legacy" implementation in terms of the "sfio" library. Used for some specialist applications on Unix machines ("sfio" is not widely ported away from Unix). Most of above are #define'd to the sfio functions. PerlIO * is in this case Sfio_t *. =item 3. USE_PERLIO Introduced just after perl5.7.0, this is a re-implementation of the above abstraction which allows perl more control over how IO is done as it decouples IO from the way the operating system and C library choose to do things. For USE_PERLIO PerlIO * has an extra layer of indirection - it is a pointer-to-a-pointer. This allows the PerlIO * to remain with a known value while swapping the implementation around underneath I. In this case all the above are true (but very simple) functions which call the underlying implementation. This is the only implementation for which C does anything "interesting". The USE_PERLIO implementation is described in L. =back Because "perlio.h" is a thin layer (for efficiency) the semantics of these functions are somewhat dependent on the underlying implementation. Where these variations are understood they are noted below. Unless otherwise noted, functions return 0 on success, or a negative value (usually C which is usually -1) and set C on error. =over 4 =item B, B, B Use these rather than C, C, C. They are written to look like "function calls" rather than variables because this makes it easier to I function calls if platform cannot export data to loaded modules, or if (say) different "threads" might have different values. =item B, B These correspond to fopen()/fdopen() and the arguments are the same. Return C and set C if there is an error. There may be an implementation limit on the number of open handles, which may be lower than the limit on the number of open files - C may not be set when C is returned if this limit is exceeded. =item B While this currently exists in all three implementations perl itself does not use it. I Perl prefers to C the new low-level descriptor to the descriptor used by the existing PerlIO. This may become the behaviour of this function in the future. =item B, B These are fprintf()/vfprintf() equivalents. =item B This is printf() equivalent. printf is #defined to this function, so it is (currently) legal to use C in perl sources. =item B, B These correspond functionally to fread() and fwrite() but the arguments and return values are different. The PerlIO_read() and PerlIO_write() signatures have been modeled on the more sane low level read() and write() functions instead: The "file" argument is passed first, there is only one "count", and the return value can distinguish between error and C. Returns a byte count if successful (which may be zero or positive), returns negative value and sets C on error. Depending on implementation C may be C if operation was interrupted by a signal. =item B Depending on implementation C may be C if operation was interrupted by a signal. =item B, B These correspond to fputs() and fputc(). Note that arguments have been revised to have "file" first. =item B This corresponds to ungetc(). Note that arguments have been revised to have "file" first. Arranges that next read operation will return the byte B. Despite the implied "character" in the name only values in the range 0..0xFF are defined. Returns the byte B on success or -1 (C) on error. The number of bytes that can be "pushed back" may vary, only 1 character is certain, and then only if it is the last character that was read from the handle. =item B This corresponds to getc(). Despite the c in the name only byte range 0..0xFF is supported. Returns the character read or -1 (C) on error. =item B This corresponds to feof(). Returns a true/false indication of whether the handle is at end of file. For terminal devices this may or may not be "sticky" depending on the implementation. The flag is cleared by PerlIO_seek(), or PerlIO_rewind(). =item B This corresponds to ferror(). Returns a true/false indication of whether there has been an IO error on the handle. =item B This corresponds to fileno(), note that on some platforms, the meaning of "fileno" may not match Unix. Returns -1 if the handle has no open descriptor associated with it. =item B This corresponds to clearerr(), i.e., clears 'error' and (usually) 'eof' flags for the "stream". Does not return a value. =item B This corresponds to fflush(). Sends any buffered write data to the underlying file. If called with C this may flush all open streams (or core dump with some USE_STDIO implementations). Calling on a handle open for read only, or on which last operation was a read of some kind may lead to undefined behaviour on some USE_STDIO implementations. The USE_PERLIO (layers) implementation tries to behave better: it flushes all open streams when passed C, and attempts to retain data on read streams either in the buffer or by seeking the handle to the current logical position. =item B This corresponds to fseek(). Sends buffered write data to the underlying file, or discards any buffered read data, then positions the file descriptor as specified by B and B (sic). This is the correct thing to do when switching between read and write on the same handle (see issues with PerlIO_flush() above). Offset is of type C which is a perl Configure value which may not be same as stdio's C. =item B This corresponds to ftell(). Returns the current file position, or (Off_t) -1 on error. May just return value system "knows" without making a system call or checking the underlying file descriptor (so use on shared file descriptors is not safe without a PerlIO_seek()). Return value is of type C which is a perl Configure value which may not be same as stdio's C. =item B, B These correspond (loosely) to fgetpos() and fsetpos(). Rather than stdio's Fpos_t they expect a "Perl Scalar Value" to be passed. What is stored there should be considered opaque. The layout of the data may vary from handle to handle. When not using stdio or if platform does not have the stdio calls then they are implemented in terms of PerlIO_tell() and PerlIO_seek(). =item B This corresponds to rewind(). It is usually defined as being PerlIO_seek(f,(Off_t)0L, SEEK_SET); PerlIO_clearerr(f); =item B This corresponds to tmpfile(), i.e., returns an anonymous PerlIO or NULL on error. The system will attempt to automatically delete the file when closed. On Unix the file is usually C-ed just after it is created so it does not matter how it gets closed. On other systems the file may only be deleted if closed via PerlIO_close() and/or the program exits via C. Depending on the implementation there may be "race conditions" which allow other processes access to the file, though in general it will be safer in this regard than ad. hoc. schemes. =item B This corresponds to setlinebuf(). Does not return a value. What constitutes a "line" is implementation dependent but usually means that writing "\n" flushes the buffer. What happens with things like "this\nthat" is uncertain. (Perl core uses it I when "dumping"; it has nothing to do with $| auto-flush.) =back =head2 Co-existence with stdio There is outline support for co-existence of PerlIO with stdio. Obviously if PerlIO is implemented in terms of stdio there is no problem. However in other cases then mechanisms must exist to create a FILE * which can be passed to library code which is going to use stdio calls. The first step is to add this line: #define PERLIO_NOT_STDIO 0 I including any perl header files. (This will probably become the default at some point). That prevents "perlio.h" from attempting to #define stdio functions onto PerlIO functions. XS code is probably better using "typemap" if it expects FILE * arguments. The standard typemap will be adjusted to comprehend any changes in this area. =over 4 =item B Used to get a PerlIO * from a FILE *. The mode argument should be a string as would be passed to fopen/PerlIO_open. If it is NULL then - for legacy support - the code will (depending upon the platform and the implementation) either attempt to empirically determine the mode in which I is open, or use "r+" to indicate a read/write stream. Once called the FILE * should I be closed by calling C on the returned PerlIO *. The PerlIO is set to textmode. Use PerlIO_binmode if this is not the desired mode. This is B the reverse of PerlIO_exportFILE(). =item B Given a PerlIO * create a 'native' FILE * suitable for passing to code expecting to be compiled and linked with ANSI C I. The mode argument should be a string as would be passed to fopen/PerlIO_open. If it is NULL then - for legacy support - the FILE * is opened in same mode as the PerlIO *. The fact that such a FILE * has been 'exported' is recorded, (normally by pushing a new :stdio "layer" onto the PerlIO *), which may affect future PerlIO operations on the original PerlIO *. You should not call C on the file unless you call C to disassociate it from the PerlIO *. (Do not use PerlIO_importFILE() for doing the disassociation.) Calling this function repeatedly will create a FILE * on each call (and will push an :stdio layer each time as well). =item B Calling PerlIO_releaseFILE informs PerlIO that all use of FILE * is complete. It is removed from the list of 'exported' FILE *s, and the associated PerlIO * should revert to its original behaviour. Use this to disassociate a file from a PerlIO * that was associated using PerlIO_exportFILE(). =item B Returns a native FILE * used by a stdio layer. If there is none, it will create one with PerlIO_exportFILE. In either case the FILE * should be considered as belonging to PerlIO subsystem and should only be closed by calling C. =back =head2 "Fast gets" Functions In addition to standard-like API defined so far above there is an "implementation" interface which allows perl to get at internals of PerlIO. The following calls correspond to the various FILE_xxx macros determined by Configure - or their equivalent in other implementations. This section is really of interest to only those concerned with detailed perl-core behaviour, implementing a PerlIO mapping or writing code which can make use of the "read ahead" that has been done by the IO system in the same way perl does. Note that any code that uses these interfaces must be prepared to do things the traditional way if a handle does not support them. =over 4 =item B Returns true if implementation has all the interfaces required to allow perl's C to "bypass" normal IO mechanism. This can vary from handle to handle. PerlIO_fast_gets(f) = PerlIO_has_cntptr(f) && \ PerlIO_canset_cnt(f) && \ 'Can set pointer into buffer' =item B Implementation can return pointer to current position in the "buffer" and a count of bytes available in the buffer. Do not use this - use PerlIO_fast_gets. =item B Return count of readable bytes in the buffer. Zero or negative return means no more bytes available. =item B Return pointer to next readable byte in buffer, accessing via the pointer (dereferencing) is only safe if PerlIO_get_cnt() has returned a positive value. Only positive offsets up to value returned by PerlIO_get_cnt() are allowed. =item B Set pointer into buffer, and a count of bytes still in the buffer. Should be used only to set pointer to within range implied by previous calls to C and C. The two values I be consistent with each other (implementation may only use one or the other or may require both). =item B Implementation can adjust its idea of number of bytes in the buffer. Do not use this - use PerlIO_fast_gets. =item B Obscure - set count of bytes in the buffer. Deprecated. Only usable if PerlIO_canset_cnt() returns true. Currently used in only doio.c to force count less than -1 to -1. Perhaps should be PerlIO_set_empty or similar. This call may actually do nothing if "count" is deduced from pointer and a "limit". Do not use this - use PerlIO_set_ptrcnt(). =item B Returns true if implementation has a buffer, and can return pointer to whole buffer and its size. Used by perl for B<-T> / B<-B> tests. Other uses would be very obscure... =item B Return I of buffer. Access only positive offsets in the buffer up to the value returned by PerlIO_get_bufsiz(). =item B Return the I in the buffer, this is neither the number that can be read, nor the amount of memory allocated to the buffer. Rather it is what the operating system and/or implementation happened to C (or whatever) last time IO was requested. =back =head2 Other Functions =over 4 =item PerlIO_apply_layers(f,mode,layers) The new interface to the USE_PERLIO implementation. The layers ":crlf" and ":raw" are only ones allowed for other implementations and those are silently ignored. (As of perl5.8 ":raw" is deprecated.) Use PerlIO_binmode() below for the portable case. =item PerlIO_binmode(f,ptype,imode,layers) The hook used by perl's C operator. B is perl's character for the kind of IO: =over 8 =item 'E' read =item 'E' write =item '+' read/write =back B is C or C. B is a string of layers to apply, only ":crlf" makes sense in the non USE_PERLIO case. (As of perl5.8 ":raw" is deprecated in favour of passing NULL.) Portable cases are: PerlIO_binmode(f,ptype,O_BINARY,NULL); and PerlIO_binmode(f,ptype,O_TEXT,":crlf"); On Unix these calls probably have no effect whatsoever. Elsewhere they alter "\n" to CR,LF translation and possibly cause a special text "end of file" indicator to be written or honoured on read. The effect of making the call after doing any IO to the handle depends on the implementation. (It may be ignored, affect any data which is already buffered as well, or only apply to subsequent data.) =item PerlIO_debug(fmt,...) PerlIO_debug is a printf()-like function which can be used for debugging. No return value. Its main use is inside PerlIO where using real printf, warn() etc. would recursively call PerlIO and be a problem. PerlIO_debug writes to the file named by $ENV{'PERLIO_DEBUG'} typical use might be Bourne shells (sh, ksh, bash, zsh, ash, ...): PERLIO_DEBUG=/dev/tty ./perl somescript some args Csh/Tcsh: setenv PERLIO_DEBUG /dev/tty ./perl somescript some args If you have the "env" utility: env PERLIO_DEBUG=/dev/tty ./perl somescript some args Win32: set PERLIO_DEBUG=CON perl somescript some args If $ENV{'PERLIO_DEBUG'} is not set PerlIO_debug() is a no-op. =back