Bug #79060 [Csd->Nab]: fgets errno=22

Edit report at https://bugs.php.net/bug.php?id=79060&edit=1 ID: 79060 Updated by: cmb@php.net Reported by: namiltd at yahoo dot com Summary: fgets errno=22 -Status: Closed +Status: Not a bug Type: Bug Package: *General Issues Operating System: Debian GNU/Linux 9 PHP Version: 7.4.1 Block user comment: N Private report: N Previous Comments: ------------------------------------------------------------------------ [2020-01-03 15:50:45] namiltd at yahoo dot com Everything clear, thank you for the explanation. ------------------------------------------------------------------------ [2020-01-03 15:42:48] nikic@php.net is_readable() tells you whether you have "r" permissions on the path (which you clearly do, as the fopen is successful). It does not tell you whether actually reading from the FD will be successful. (A simple example is a directory -- on Linux these will fopen fine, but fail reading with errno 21.) The behavior of /sys files is determined by the kernel and/or device drivers. This particular file happens to reject reads with errno 22. That's just how things are. If you try to "cat /sys/class/net/lo/speed" you'll get exactly the same result. ------------------------------------------------------------------------ [2020-01-03 15:20:45] namiltd at yahoo dot com But is_readable("/sys/class/net/lo/speed") returns true Try: <?php $fname = "/sys/class/net/lo/speed"; $file = fopen($fname, "r"); if (is_readable($fname)) { echo ">".fgets($file, 2048)."<"; } else { echo "File is not readable"; } fclose($file); ------------------------------------------------------------------------ [2020-01-03 14:43:19] nikic@php.net What is the bug here? The fgets() fails because the "file" is not readable. Since PHP 7.4, file system read/write failures result in a notice and false return value (this is noted in the upgrading notes). ------------------------------------------------------------------------ [2020-01-03 13:24:07] namiltd at yahoo dot com E-mail change ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=79060 -- Edit this bug report at https://bugs.php.net/bug.php?id=79060&edit=1