** Also affects: linux (Ubuntu Wily) Importance: Medium Assignee: Andy Whitcroft (apw) Status: In Progress
** Changed in: linux (Ubuntu Wily) Status: In Progress => Fix Committed -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1483440 Title: odd behavior with /proc/net/route reading via sh 'read' Status in linux package in Ubuntu: Fix Committed Status in linux source package in Wily: Fix Committed Bug description: I saw some strange behavior when one of my scripts started failing to get the data it was looking for out of /proc/net/route $ uname -r $ dpkg -S /boot/vmlinux-$(uname -r) linux-image-4.1.0-3-generic: /boot/vmlinuz-4.1.0-3-generic $ id -u 1000 $ cp /proc/net/route /tmp/route $ diff /proc/net/route /tmp/route $ md5sum /proc/net/route /tmp/route 4b3663ec7554cf91764106ea9dcc2ada /proc/net/route 4b3663ec7554cf91764106ea9dcc2ada /tmp/route ## just cat the file $ cat /proc/net/route Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT eth0 00000000 01A8F50A 0003 0 0 0 00000000 00 0 eth0 00A8F50A 00000000 0001 0 0 0 00F8FFFF 00 0 virbr0 007AA8C0 00000000 0001 0 0 0 00FFFFFF 00 0 ## try to read it with sh while loop $ sh -c 'while read line; do echo line: $line; done' < /proc/net/route line: Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT line: eth0 00A8F50A 00000000 0001 0 0 0 00F8FFFF 0 0 0 line: virbr0 007AA8C0 00000000 0001 0 0 0 00FFFFFF 0 0 0 ## odd, where did the first line go? ## ## maybe its still there if we cat $ cat /proc/net/route | sh -c 'while read line; do echo line: $line; done' line: Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT line: eth0 00000000 01A8F50A 0003 0 0 0 00000000 0 0 0 line: eth0 00A8F50A 00000000 0001 0 0 0 00F8FFFF 0 0 0 line: virbr0 007AA8C0 00000000 0001 0 0 0 00FFFFFF 0 0 0 ## Yep, still there. ## as expected, the copied file shows sane behavior $ sh -c 'while read line; do echo line: $line; done' < /tmp/route line: Iface Destination Gateway Flags RefCnt Use Metric Mask MTU Window IRTT line: eth0 00000000 01A8F50A 0003 0 0 0 00000000 0 0 0 line: eth0 00A8F50A 00000000 0001 0 0 0 00F8FFFF 0 0 0 line: virbr0 007AA8C0 00000000 0001 0 0 0 00FFFFFF 0 0 0 ProblemType: Bug DistroRelease: Ubuntu 15.10 Package: linux-image-4.1.0-3-generic 4.1.0-3.3 ProcVersionSignature: User Name 4.1.0-3.3-generic 4.1.3 Uname: Linux 4.1.0-3-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Aug 10 23:52 seq crw-rw---- 1 root audio 116, 33 Aug 10 23:52 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.18-0ubuntu6 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: Date: Mon Aug 10 23:55:09 2015 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' MachineType: HP ProLiant DL360 Gen9 PciMultimedia: ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_US.UTF-8 SHELL=/bin/bash ProcFB: 0 EFI VGA ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.1.0-3-generic root=UUID=ebea97f1-7014-4fac-bc87-c8ff465c566f ro --- console=ttyS1,115200 RelatedPackageVersions: linux-restricted-modules-4.1.0-3-generic N/A linux-backports-modules-4.1.0-3-generic N/A linux-firmware 1.146 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev' UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 03/05/2015 dmi.bios.vendor: HP dmi.bios.version: P89 dmi.chassis.type: 23 dmi.chassis.vendor: HP dmi.modalias: dmi:bvnHP:bvrP89:bd03/05/2015:svnHP:pnProLiantDL360Gen9:pvr:cvnHP:ct23:cvr: dmi.product.name: ProLiant DL360 Gen9 dmi.sys.vendor: HP To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1483440/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp