To compute the number of milliseconds per day, you can use the following snippets:
Java
final long millisecondsPerDay = 24 /*hours*/ * 60 /*minutes*/ * 60 /*seconds*/ * 1000 /*milliseconds*/;
C/C++
const unsigned long millisecondsPerDay = 24 /*hours*/ * 60 /*minutes*/ * 60 /*seconds*/ * 1000 /*milliseconds*/;
Recently we tried to install some packages from the Android SDK through Android Studio 3.0.1 and we got the error that the PC ran out of space while downloading the necessary packages and could not perform the operation.
Full Error Log:
To install: - Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86) Preparing "Install Google APIs Intel x86 Atom System Image (revision: 2)". Downloading https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip An error occurred while preparing SDK package Google APIs Intel x86 Atom System Image: Cannot download 'https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip': No space left on device , response: 200 OK. "Install Google APIs Intel x86 Atom System Image (revision: 2)" failed. Failed packages: - Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86)
Although the disk had a lot of free space, we got this error because the /tmp partition on our GNU/Linux Fedora 27 workstation was too small (~4GB).
$ df -h; Filesystem Size Used Avail Use% Mounted on devtmpfs 3.9G 0 3.9G 0% /dev tmpfs 3.9G 107M 3.8G 3% /dev/shm tmpfs 3.9G 1.9M 3.9G 1% /run tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup /dev/mapper/fedora-root 50G 35G 12G 75% / tmpfs 3.9G 2.1M 3.9G 1% /tmp /dev/sdb1 477M 179M 269M 41% /boot /dev/mapper/fedora-home 178G 37G 132G 22% /home tmpfs 794M 16K 794M 1% /run/user/42 tmpfs 794M 9.2M 785M 2% /run/user/1000
/tmp was not explicitly set so it was automatically configured to have half of the size of the RAM.
We didn’t not want to change the download path for the Java environment (and hence Android Studio and Android SDK tools) as after leaving the tmpfs folder it could mean that we would have to manually maintain the new path and clean it up. So we ended up in temporarily increasing the size of /tmp partition which did the trick and the virtual device was installed successfully.
The command we used to increase the size of the /tmp partition on Fedora 27 was the following:
sudo mount -o remount,size=8G,noatime /tmp;
After executing we, it we immediately saw that the results were applied without the need for a restart or any other operation and we could proceed to use the PC as normal.
$ df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 3.9G 0 3.9G 0% /dev tmpfs 3.9G 89M 3.8G 3% /dev/shm tmpfs 3.9G 1.9M 3.9G 1% /run tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup /dev/mapper/fedora-root 50G 35G 12G 75% / tmpfs 8.0G 2.0M 8.0G 1% /tmp /dev/sdb1 477M 179M 269M 41% /boot /dev/mapper/fedora-home 178G 37G 132G 22% /home tmpfs 794M 16K 794M 1% /run/user/42 tmpfs 794M 6.9M 787M 1% /run/user/1000
The information for tmpfs we got it from: https://wiki.archlinux.org/index.php/Tmpfs
Full Correct Execution Log:
To install: - Google APIs Intel x86 Atom System Image (system-images;android-27;google_apis;x86) Preparing "Install Google APIs Intel x86 Atom System Image (revision: 2)". Downloading https://dl.google.com/android/repository/sys-img/google_apis/x86-27_r02.zip "Install Google APIs Intel x86 Atom System Image (revision: 2)" ready. Installing Google APIs Intel x86 Atom System Image in /home/xeirwn/Android/Sdk/system-images/android-27/google_apis/x86 "Install Google APIs Intel x86 Atom System Image (revision: 2)" complete. "Install Google APIs Intel x86 Atom System Image (revision: 2)" finished.
Recently we needed to process the results of a tcpdump command using the GUI version of WireShark on machine that did not have a window manager installed. That device was an embedded device, for which it did not make sense to even consider installing a window manager on it. So, in order to process the results of the tcpdump command we decided to use another machine that had a full working window manager installed and was able to operate the GUI version of WireShark.
For our solution to work some requirements were expected to be met by the embedded device (a.k.a. remote machine).
tcpdump was installed on the remote machinessh server was installed on the remote machine and allowed us to connect to it remotelytcpdump on the needed interfacesJust execute the following on the machine with the GUI (a.k.a. local machine)
mkfifo /tmp/board; wireshark -k -i /tmp/board & ssh [email protected] "tcpdump -s 0 -U -n -w - -i lo not port 22" > /tmp/board;
Following are the steps that we performed on the local machine to pipe the results of tcpdump on the remote machine on the wireshark on the local machine.
named pipe as follows:mkfifo /tmp/board;pipe anyway you like and place it in any folder you wish. We used /tmp as our pipe is a temporary construct that we do not care to preserve across time/restarts.wireshark from a terminal so that we could pass as capture interface the named pipe we just created using the -i /tmp/board parameter. The -k parameter instructs wireshark to start the capture session immediately.wireshark -k -i /tmp/board && symbol at the end of the command.tcpdump over ssh on a board and redirected its output to our named pipe.ssh [email protected] "tcpdump -s 0 -U -n -w - -i lo not port 22" > /tmp/board;tcpdump have the following effects:-s 0 instructs tcpdump to set the snapshot length of data from each packet to the default value of 262144 bytes.-U Since the -w option is not specified, make the printed packet output packet-buffered. Which means that it will print the description of the contents of each packet without waiting for the output buffer to get full.-n Does not convert host addresses to names. This can be used to avoid DNS lookups.-w - Write the raw packets to Standard Output rather than parsing them.-i lo Defines which interface to listen on. We wanted the loopback interface to listen to everything.not port 22 Since we used ssh to start this command, we do not want to listen to the data that we produce as well and flood the inputs.
