In Perl, how to get the epoch timestamp, the number of seconds passed since the epoch?
In Perl, to get the epoch time, call the time function:
my $ts = time
Example:
$ perl -e 'print time . "n"'
1491473202
How to iterate all files and directories under a directory in Python? For example, I would like to iterate each file and directory under /mnt/data/ /mnt/data/ |– file.txt `– great That is: /mnt/data/files.txt /mnt/data/great You can use the os.walk to do this: root, dirs, files = os.walk(path).next() root will be the path.dirs will contain the…
PNG images already use DEFLATE data compression algorithm involving a combination of LZ77 and Huffman coding. But the PNG images can be further compressed by removing non-important metadata or using lossy compression to save storage space and/or data transfer bandwidth. In this post, we introduce 2 compression ways with tools available on Linux. Lossless compression…
I have multiple jpg images as files like 001.jpg, 002.jpg … How to merge multiple jpg images to a pdf on Linux? convert is your good friend: convert *.jpg output.pdf Read more: How to merge multiple PDF files to a PDF on Linux? How to convert .pptx slides to .jpg or .png images on Linux…
How to use iPhone to browse blocked websites in mainland China? FYI: on iPhone, these 2 Apps are the favorite combination I am using for visiting blocked websites in mainland China: Check OpenVPN + Ovpn Spider: Free VPNs for iPhone Users for how to use them together. OpenVPN is for setting up OpenVPN VPN connection….
How to manage users and repositories and how to use these repositories will be introduced in this post. Please refer to Setting Up a Git Server Using Gitosis for how to set up the git server. Please refer to Howto for New Git Users for how to use git as a new user. Create a…
How to deactivate a LVM logical volume activated by #vgchange -aay on Linux You may need to make a LVM volume group inactive and thus unknown to the kernel. To deactivate a volume group, use the -a (–activate) argument of the vgchange command. To deactivates the volume group vg, use this command # vgchange -a…