Use the sleep command. Example: sleep .5 # Waits 0.5 second. sleep 5 # Waits 5 seconds. sleep 5s # Waits 5 seconds. sleep 5m # Waits 5 minutes. sleep 5h # Waits 5 hours. sleep 5d # Waits 5 days. One can also employ decimals when specifying a time unit; e.g. sleep 1.5s
POSIX is a family of standards, specified by the IEEE, to clarify and make uniform the application programming interfaces (and ancillary issues, such as commandline shell utilities) provided by Unix-y operating systems. When you write your programs to rely on POSIX standards, you can be pretty sure to be able to port them easily among … Read more
You need to add it to your ~/.profile or ~/.bashrc file. export PATH=”$PATH:/path/to/dir” Depending on what you’re doing, you also may want to symlink to binaries: cd /usr/bin sudo ln -s /path/to/binary binary-name Note that this will not automatically update your path for the remainder of the session. To do this, you should run: source … Read more
Try something like: du -sh * short version of: du –summarize –human-readable * Explanation: du: Disk Usage -s: Display a summary for each specified file. (Equivalent to -d 0) -h: “Human-readable” output. Use unit suffixes: Byte, Kibibyte (KiB), Mebibyte (MiB), Gibibyte (GiB), Tebibyte (TiB) and Pebibyte (PiB). (BASE2)
This fuser 8080/tcp will print you PID of process bound on that port. And this fuser -k 8080/tcp will kill that process. Works on Linux only. More universal is use of lsof -i4 (or 6 for IPv6).
Short answer: $ ssh-keygen -p This will then prompt you to enter the keyfile location, the old passphrase, and the new passphrase (which can be left blank to have no passphrase). If you would like to do it all on one line without prompts do: $ ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile] Important: … Read more
This looks like a permissions issue in your home directory. To reclaim ownership of the .npm directory execute: sudo chown -R $(whoami) ~/.npm
What is sh? sh (or the Shell Command Language) is a programming language described by the POSIX standard. It has many implementations (ksh88, Dash, …). Bash can also be considered an implementation of sh (see below). Because sh is a specification, not an implementation, /bin/sh is a symlink (or a hard link) to an actual … Read more
Because that’s how the POSIX standard defines a line: 3.206 Line A sequence of zero or more non- <newline> characters plus a terminating <newline> character. Therefore, lines not ending in a newline character aren’t considered actual lines. That’s why some programs have problems processing the last line of a file if it isn’t newline terminated. … Read more
One way to do it is: while read p; do echo “$p” done <peptides.txt As pointed out in the comments, this has the side effects of trimming leading whitespace, interpreting backslash sequences, and skipping the last line if it’s missing a terminating linefeed. If these are concerns, you can do: while IFS=”” read -r p … Read more