Closed p5pRT closed 6 years ago
This is a bug report for perl from jim.avera@gmail.com\, generated with the help of perlbug 1.40 running under perl 5.24.1.
If print is called with $fh instead of an old-style FILEHANDLE (no comma in either case)\, then a Syntax Error occurs if the first data item is \<$fh>.
print $outfh \<$infh> #Syntax Error
No error occurs if $outfh or $infh is replaced by HANDLE\, of if \<$infh> is not the first data item.
#!/usr/bin/perl use strict; use warnings; require File::Temp;
open INFH\, "\<"\, "/etc/timezone" or die; open my $infh\, "\<"\, "/etc/timezone" or die;
open OUTFH\, ">&STDOUT" or die; open my $outfh\, ">&STDOUT" or die;
local $/; #slurp
print $outfh \<$infh> or die; # SYNTAX ERROR
print $outfh "fooey"\, \<$infh> or die; # ok
print $outfh \
Flags: category=core severity=low
Site configuration information for perl 5.24.1:
Configured by Debian Project at Sat Mar 18 17:00:39 UTC 2017.
Summary of my perl5 (revision 5 version 24 subversion 1) configuration:
Platform: osname=linux\, osvers=3.16.0\, archname=x86_64-linux-gnu-thread-multi uname='linux localhost 3.16.0 #1 smp debian 3.16.0 x86_64 gnulinux ' config_args='-Dusethreads -Duselargefiles -Dcc=x86_64-linux-gnu-gcc -Dcpp=x86_64-linux-gnu-cpp -Dld=x86_64-linux-gnu-gcc -Dccflags=-DDEBIAN -Wdate-time -D_FORTIFY_SOURCE=2 -g -O2 -fdebug-prefix-map=/build/perl-gaNj0t/perl-5.24.1=. -fstack-protector-strong -Wformat -Werror=format-security -Dldflags= -Wl\,-Bsymbolic-functions -Wl\,-z\,relro -Dlddlflags=-shared -Wl\,-Bsymbolic-functions -Wl\,-z\,relro -Dcccdlflags=-fPIC -Darchname=x86_64-linux-gnu -Dprefix=/usr -Dprivlib=/usr/share/perl/5.24 -Darchlib=/usr/lib/x86_64-linux-gnu/perl/5.24 -Dvendorprefix=/usr -Dvendorlib=/usr/share/perl5 -Dvendorarch=/usr/lib/x86_64-linux-gnu/perl5/5.24 -Dsiteprefix=/usr/local -Dsitelib=/usr/local/share/perl/5.24.1 -Dsitearch=/usr/local/lib/x86_64-linux-gnu/perl/5.24.1 -Dman1dir=/usr/share/man/man1 -Dman3dir=/usr/share/man/man3 -Dsiteman1dir=/usr/local/man/man1 -Dsiteman3dir=/usr/local/man/man3 -Dusesitecustomize -Duse64bitint -Dman1ext=1 -Dman3ext=3perl -Dpager=/usr/bin/sensible-pager -Uafs -Ud_csh -Ud_ualarm -Uusesfio -Uusenm -Ui_libutil -Uversiononly -DDEBUGGING=-g -Doptimize=-O2 -dEs -Duseshrplib -Dlibperl=libperl.so.5.24.1' hint=recommended\, useposix=true\, d_sigaction=define useithreads=define\, usemultiplicity=define use64bitint=define\, use64bitall=define\, uselongdouble=undef usemymalloc=n\, bincompat5005=undef Compiler: cc='x86_64-linux-gnu-gcc'\, ccflags ='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64'\, optimize='-O2 -g'\, cppflags='-D_REENTRANT -D_GNU_SOURCE -DDEBIAN -fwrapv -fno-strict-aliasing -pipe -I/usr/local/include' ccversion=''\, gccversion='6.3.0 20170316'\, gccosandvers='' intsize=4\, longsize=8\, ptrsize=8\, doublesize=8\, byteorder=12345678\, doublekind=3 d_longlong=define\, longlongsize=8\, d_longdbl=define\, longdblsize=16\, longdblkind=3 ivtype='long'\, ivsize=8\, nvtype='double'\, nvsize=8\, Off_t='off_t'\, lseeksize=8 alignbytes=8\, prototype=define Linker and Libraries: ld='x86_64-linux-gnu-gcc'\, ldflags =' -fstack-protector-strong -L/usr/local/lib' libpth=/usr/local/lib /usr/lib/gcc/x86_64-linux-gnu/6/include-fixed /usr/include/x86_64-linux-gnu /usr/lib /lib/x86_64-linux-gnu /lib/../lib /usr/lib/x86_64-linux-gnu /usr/lib/../lib /lib libs=-lgdbm -lgdbm_compat -ldb -ldl -lm -lpthread -lc -lcrypt perllibs=-ldl -lm -lpthread -lc -lcrypt libc=libc-2.24.so\, so=so\, useshrplib=true\, libperl=libperl.so.5.24 gnulibc_version='2.24' Dynamic Linking: dlsrc=dl_dlopen.xs\, dlext=so\, d_dlsymun=undef\, ccdlflags='-Wl\,-E' cccdlflags='-fPIC'\, lddlflags='-shared -L/usr/local/lib -fstack-protector-strong'
Locally applied patches: DEBPKG:debian/cpan_definstalldirs - Provide a sensible INSTALLDIRS default for modules installed from CPAN. DEBPKG:debian/db_file_ver - https://bugs.debian.org/340047 Remove overly restrictive DB_File version check. DEBPKG:debian/doc_info - Replace generic man(1) instructions with Debian-specific information. DEBPKG:debian/enc2xs_inc - https://bugs.debian.org/290336 Tweak enc2xs to follow symlinks and ignore missing @INC directories. DEBPKG:debian/errno_ver - https://bugs.debian.org/343351 Remove Errno version check due to upgrade problems with long-running processes. DEBPKG:debian/libperl_embed_doc - https://bugs.debian.org/186778 Note that libperl-dev package is required for embedded linking DEBPKG:fixes/respect_umask - Respect umask during installation DEBPKG:debian/writable_site_dirs - Set umask approproately for site install directories DEBPKG:debian/extutils_set_libperl_path - EU:MM: set location of libperl.a under /usr/lib DEBPKG:debian/no_packlist_perllocal - Don't install .packlist or perllocal.pod for perl or vendor DEBPKG:debian/fakeroot - Postpone LD_LIBRARY_PATH evaluation to the binary targets. DEBPKG:debian/instmodsh_doc - Debian policy doesn't install .packlist files for core or vendor. DEBPKG:debian/ld_run_path - Remove standard libs from LD_RUN_PATH as per Debian policy. DEBPKG:debian/libnet_config_path - Set location of libnet.cfg to /etc/perl/Net as /usr may not be writable. DEBPKG:debian/mod_paths - Tweak @INC ordering for Debian DEBPKG:debian/prune_libs - https://bugs.debian.org/128355 Prune the list of libraries wanted to what we actually need. DEBPKG:fixes/net_smtp_docs - [rt.cpan.org #36038] https://bugs.debian.org/100195 Document the Net::SMTP 'Port' option DEBPKG:debian/perlivp - https://bugs.debian.org/510895 Make perlivp skip include directories in /usr/local DEBPKG:debian/deprecate-with-apt - https://bugs.debian.org/747628 Point users to Debian packages of deprecated core modules DEBPKG:debian/squelch-locale-warnings - https://bugs.debian.org/508764 Squelch locale warnings in Debian package maintainer scripts DEBPKG:debian/skip-upstream-git-tests - Skip tests specific to the upstream Git repository DEBPKG:debian/patchlevel - https://bugs.debian.org/567489 List packaged patches for 5.24.1-2ubuntu1 in patchlevel.h DEBPKG:debian/skip-kfreebsd-crash - https://bugs.debian.org/628493 [perl #96272] Skip a crashing test case in t/op/threads.t on GNU/kFreeBSD DEBPKG:fixes/document_makemaker_ccflags - https://bugs.debian.org/628522 [rt.cpan.org #68613] Document that CCFLAGS should include $Config{ccflags} DEBPKG:debian/find_html2text - https://bugs.debian.org/640479 Configure CPAN::Distribution with correct name of html2text DEBPKG:debian/perl5db-x-terminal-emulator.patch - https://bugs.debian.org/668490 Invoke x-terminal-emulator rather than xterm in perl5db.pl DEBPKG:debian/cpan-missing-site-dirs - https://bugs.debian.org/688842 Fix CPAN::FirstTime defaults with nonexisting site dirs if a parent is writable DEBPKG:fixes/memoize_storable_nstore - [rt.cpan.org #77790] https://bugs.debian.org/587650 Memoize::Storable: respect 'nstore' option not respected DEBPKG:debian/regen-skip - Skip a regeneration check in unrelated git repositories DEBPKG:debian/makemaker-pasthru - https://bugs.debian.org/758471 Pass LD settings through to subdirectories DEBPKG:debian/makemaker-manext - https://bugs.debian.org/247370 Make EU::MakeMaker honour MANnEXT settings in generated manpage headers DEBPKG:debian/devel-ppport-reproducibility - https://bugs.debian.org/801523 Sort the list of XS code files when generating RealPPPort.xs DEBPKG:debian/encode-unicode-bom-doc - https://bugs.debian.org/798727 Document Debian backport of Encode::Unicode fix DEBPKG:debian/kfreebsd-softupdates - https://bugs.debian.org/796798 Work around Debian Bug#796798 DEBPKG:fixes/autodie-scope - https://bugs.debian.org/798096 Fix a scoping issue with "no autodie" and the "system" sub DEBPKG:fixes/crosscompile-no-targethost - [23695c0] [perl #127234] Fix the Configure escape with usecrosscompile but no targethost DEBPKG:fixes/memoize-pod - [rt.cpan.org #89441] Fix POD errors in Memoize DEBPKG:fixes/ok-pod - Added encoding for pod. DEBPKG:debian/hurd-softupdates - https://bugs.debian.org/822735 Fix t/op/stat.t failures on hurd DEBPKG:fixes/nntp_docs - https://bugs.debian.org/51962 Net::NNTP: Correct innd/nnrpd confusion in relation to Reader option DEBPKG:fixes/math_complex_doc_great_circle - https://bugs.debian.org/697567 [rt.cpan.org #114104] Math::Trig: clarify definition of great_circle_midpoint DEBPKG:fixes/math_complex_doc_see_also - https://bugs.debian.org/697568 [rt.cpan.org #114105] Math::Trig: add missing SEE ALSO DEBPKG:fixes/math_complex_doc_angle_units - https://bugs.debian.org/731505 [rt.cpan.org #114106] Math::Trig: document angle units DEBPKG:fixes/cpan_web_link - https://bugs.debian.org/367291 CPAN: Add link to main CPAN web site DEBPKG:fixes/time_piece_doc - https://bugs.debian.org/817925 Time::Piece: Improve documentation for add_months and add_years DEBPKG:fixes/perlbug-refactor - https://bugs.debian.org/822463 [perl #128020] perlbug: Refactor duplicated file reading code DEBPKG:fixes/perlbug-linewrap - https://bugs.debian.org/822463 [perl #128020] perlbug: wrap overly long lines DEBPKG:fixes/hurd_sigaction - https://bugs.debian.org/825016 [d54f4ed] ext/POSIX/t/sigaction.t: Skip uid and pid tests on GNU/Hurd DEBPKG:fixes/hurd_hints - [4694301] https://bugs.debian.org/825020 [perl #128279] Modify hints for Hurd per Debian ticket 825020. DEBPKG:fixes/extutils-parsexs-reproducibility - [perl #128517] https://bugs.debian.org/829296 Make the output of ExtUtils::ParseXS reproducible DEBPKG:debian/CVE-2016-1238/sitecustomize-in-etc - Look for sitecustomize.pl in /etc/perl rather than sitelib on Debian systems DEBPKG:debian/CVE-2016-1238/test-suite-without-dot - [perl #127810] Patch unit tests to explicitly insert "." into @INC when needed. DEBPKG:debian/CVE-2016-1238/eumm-without-dot - [perl #127810] Add PERL_USE_UNSAFE_INC support to EU::MM for fortify_inc support. DEBPKG:debian/CVE-2016-1238/cpan-without-dot - [perl #127810] Set PERL_USE_UNSAFE_INC for cpan usage DEBPKG:debian/document_inc_removal - Document in perlvar that we remove '.' from @INC by default DEBPKG:fixes/extutils_makemaker_reproducible - https://bugs.debian.org/835815 https://bugs.debian.org/834190 Make perllocal.pod files reproducible DEBPKG:debian/CVE-2016-1238/remove-inc-test - Remove test for '.' in @INC as it might not be DEBPKG:debian/customized - Update customized.dat for files patched in Debian DEBPKG:fixes/file_path_hurd_errno - File-Path: Fix test failure in Hurd due to hard-coded ENOENT DEBPKG:debian/hppa_op_optimize_workaround - https://bugs.debian.org/838613 Temporarily lower the optimization of op.c on hppa due to gcc-6 problems DEBPKG:fixes/test-builder-warning - https://bugs.debian.org/840968 Silence a 'used only once' warning in Test::Builder DEBPKG:fixes/longdblinf-randomness - [dd68853] [perl #130133] https://bugs.debian.org/844752 Configure: fix garbage filtering with 80-bit long doubles DEBPKG:debian/installman-utf8 - https://bugs.debian.org/840211 Generate man pages with UTF-8 characters DEBPKG:fixes/list_assign_leak - [1050723] [perl #130766] https://bugs.debian.org/855064 avoid a leak in list assign from/to magic values DEBPKG:fixes/perlfunc_inc_doc - [a03e9f8] https://bugs.debian.org/839536 [perl #130832] Documentation fixes for '.' possibly no longer being in @INC DEBPKG:fixes/Compress-Raw-Zlib-2.071-Adapt-tests-to-zlib-1.2.11.patch - [PATCH] Adapt tests to zlib 1.2.11 DEBPKG:fixes/0001-Adapt-tests-to-zlib-1.2.11.patch - [PATCH] Adapt tests to zlib 1.2.11
@INC for perl 5.24.1: /home/jima/perl5/lib/perl5/5.24.1/x86_64-linux-gnu-thread-multi /home/jima/perl5/lib/perl5/5.24.1 /home/jima/perl5/lib/perl5/x86_64-linux-gnu-thread-multi /home/jima/perl5/lib/perl5 /home/jima/lib/perl /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.24.1 /usr/local/share/perl/5.24.1 /usr/lib/x86_64-linux-gnu/perl5/5.24 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.24 /usr/share/perl/5.24 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base
Environment for perl 5.24.1: HOME=/home/jima LANG=en_US.UTF-8 LANGUAGE=en_US LC_COLLATE=C LD_LIBRARY_PATH (unset) LOGDIR (unset) PATH=/home/jima/perl5/bin:/home/jima/bin:/home/jima/jima_tools/x86_64/bin:/home/jima/jima_tools/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/bin/X11:/usr/local/bin:/usr/local/sbin:/usr/games:/usr/local/games:/usr/lib/jvm/java-8-oracle/bin:/usr/lib/jvm/java-8-oracle/db/bin:/usr/lib/jvm/java-8-oracle/jre/bin:. PERL5LIB=/home/jima/perl5/lib/perl5:/home/jima/lib/perl PERL_BADLANG (unset) PERL_LOCAL_LIB_ROOT=/home/jima/perl5 PERL_MB_OPT=--install_base "/home/jima/perl5" PERL_MM_OPT=INSTALL_BASE=/home/jima/perl5 SHELL=/bin/bash
print $outfh \<$infh> \#Syntax Error
"$outfh \<$infh" parses as a comparison expression. A syntax error of this kind is to be expected from such ambiguity; it is not a bug. You can avoid this by wrapping $outfh in braces.
-zefram
The RT System itself - Status changed from 'new' to 'open'
Ah\, thanks. I had no idea that braces were allowed to be used like that. Can you briefly explain why this is legal syntax? Is it a special case just for indirect object syntax
methodname {expr yielding object ref} args...
or is this an example of a more general concept? Normally I would expect {...} where a value is expected to be a hash constructor (obviously not the case here). So I'm surprised.
Just point me to the docs and I'll read.
Thanks again\, -Jim
On 11/11/2017 04:16 PM\, Zefram via RT wrote:
print $outfh \<$infh> \#Syntax Error
"$outfh \<$infh" parses as a comparison expression. A syntax error of this kind is to be expected from such ambiguity; it is not a bug. You can avoid this by wrapping $outfh in braces.
-zefram
Jim Avera wrote:
Can you briefly explain why this is legal syntax?
It's legal by fiat. A braced block is one of the permitted forms of indirect object. The main purpose of it is to permit an arbitrarily complicated subexpression to be used as an indirect object. It's not well documented\, but the entry for "print" in perlfunc(1) describes it\, with examples.
Normally I would expect
{...} where a value is expected to be a hash constructor (obviously not the case here).
There's an ambiguity between hash constructors and code blocks in many situations\, including here. perl guesses which is meant\, and occasionally gets it wrong. You can force the correct interpretation by opening the construct with "+{" for a hash constructor or "{;" for a code block.
-zefram
On 11/12/2017 09:20 AM\, Jim Avera wrote:
Ah\, thanks. I had no idea that braces were allowed to be used like that. Can you briefly explain why this is legal syntax? Is it a special case just for indirect object syntax
methodname {expr yielding object ref} args...
or is this an example of a more general concept? Normally I would expect {...} where a value is expected to be a hash constructor (obviously not the case here). So I'm surprised.
Just point me to the docs and I'll read.
Hi\, Jim. :)
The docs for print (perldoc -f print) include the following paragraph:
If you're storing handles in an array or hash\, or in general whenever you're using any expression more complex than a bareword handle or a plain\, unsubscripted scalar variable to retrieve it\, you will have to use a block returning the filehandle value instead\, in which case the LIST may not be omitted:
print { $files[$i] } "stuff\n"; print { $OK ? *STDOUT : *STDERR } "stuff\n";
This is what includes the ability to do (as also mentioned by Perl Best Practices) the following:
print {$fh} "foo";
@cpansprout - Status changed from 'open' to 'rejected'
Thank you Zefram & Sawyer for the explanation. I appreciate it.
Sorry for the bogus bugrep -Jim
On 11/13/2017 08:07 AM\, Jim Avera wrote:
Thank you Zefram & Sawyer for the explanation. I appreciate it.
Sorry for the bogus bugrep
Don't worry about it. :)
Migrated from rt.perl.org#132434 (status was 'rejected')
Searchable as RT132434$