If you have filesystems that support "large files" (files larger than
2 gigabytes), you may now also be able to create and access them from Perl.
-Note that in addition to requiring a proper file system to do this you
-may also need to adjust your per-process (or your per-system, or per-user-group)
-maximum filesize limits before running Perl scripts that try to handle large
-files, especially if you intend to write such files.
-
-Adjusting your file system/system limits is outside the scope of Perl.
-For process limits, you may try to increase the limits using your
-shell's limit/ulimit command before running Perl. The BSD::Resource
-extension (not included with the standard Perl distribution) may also
-be of use, it contains getrlimit/setrlimit calls.
+Note that in addition to requiring a proper file system to do large
+files you may also need to adjust your per-process (or your
+per-system, or per-process-group, or per-user-group) maximum filesize
+limits before running Perl scripts that try to handle large files,
+especially if you intend to write such files.
+
+Finally, in addition to your process/process group maximum filesize
+limits, you may have quota limits on your filesystems that stop you
+(your user id or your user group id) from using large files.
+
+Adjusting your process/user/group/file system/operating system limits
+is outside the scope of Perl core language. For process limits, you
+may try increasing the limits using your shell's limits/limit/ulimit
+command before running Perl. The BSD::Resource extension (not
+included with the standard Perl distribution) may also be of use, it
+offers the getrlimit/setrlimit interface that can be used to adjust
+process resource usage limits, including the maximum filesize limit.
(Large file support is related to 64-bit support, for obvious reasons.)
print <<EOM;
#
# If the lfs (large file support: large meaning larger than two gigabytes)
-# tests are skipped or fail, it may mean either that your process is not
-# allowed to write large files or that the file system you are running
-# the tests on doesn't support large files, or both. You may also need
-# to reconfigure your kernel. (This is all very system-dependent.)
+# tests are skipped or fail, it may mean either that your process
+# (or process group) is not allowed to write large files (resource
+# limits) or that the file system you are running the tests on doesn't
+# let your user/group have large files (quota) or the filesystem simply
+# doesn't support large files. You may even need to reconfigure your kernel.
+# (This is all very operating system and site-dependent.)
#
# Perl may still be able to support large files, once you have
-# such a process and such a (file) system.
+# such a process, enough quota, and such a (file) system.
#
EOM
}
# By now we better be sure that we do have sparse files:
# if we are not, the following will hog 5 gigabytes of disk. Ooops.
+$ENV{LC_ALL} = "C";
+
sysopen(BIG, "big", O_WRONLY|O_CREAT|O_TRUNC) or
do { warn "sysopen failed: $!\n"; bye };
sysseek(BIG, 5_000_000_000, SEEK_SET);
+
# The syswrite will fail if there are are filesize limitations (process or fs).
-unless(syswrite(BIG, "big") == 3) {
- $ENV{LC_ALL} = "C";
+my $syswrite = syswrite(BIG, "big") == 3;
+my $close = close BIG if $syswrite;
+unless($syswrite && $close) {
+ unless ($syswrite) {
+ print "# syswrite failed: $!\n"
+ } else {
+ print "# close failed: $!\n"
+ }
if ($! =~/File too large/) {
print "1..0\n# writing past 2GB failed\n";
explain();
- bye();
}
+ bye();
}
-close BIG;
@s = stat("big");
print <<EOM;
#
# If the lfs (large file support: large meaning larger than two gigabytes)
-# tests are skipped or fail, it may mean either that your process is not
-# allowed to write large files or that the file system you are running
-# the tests on doesn't support large files, or both. You may also need
-# to reconfigure your kernel. (This is all very system-dependent.)
+# tests are skipped or fail, it may mean either that your process
+# (or process group) is not allowed to write large files (resource
+# limits) or that the file system you are running the tests on doesn't
+# let your user/group have large files (quota) or the filesystem simply
+# doesn't support large files. You may even need to reconfigure your kernel.
+# (This is all very operating system and site-dependent.)
#
# Perl may still be able to support large files, once you have
-# such a process and such a (file) system.
+# such a process, enough quota, and such a (file) system.
#
EOM
}
# By now we better be sure that we do have sparse files:
# if we are not, the following will hog 5 gigabytes of disk. Ooops.
+$ENV{LC_ALL} = "C";
+
open(BIG, ">big") or do { warn "open failed: $!\n"; bye };
binmode BIG;
seek(BIG, 5_000_000_000, $SEEK_SET);
+
# Either the print or (more likely, thanks to buffering) the close will
# fail if there are are filesize limitations (process or fs).
my $print = print BIG "big";
my $close = close BIG if $print;
unless ($print && $close) {
- $ENV{LC_ALL} = "C";
+ unless ($print) {
+ print "# print failed: $!\n"
+ } else {
+ print "# close failed: $!\n"
+ }
if ($! =~/File too large/) {
print "1..0\n# writing past 2GB failed\n";
explain();