In C++11, you can do this with standard library facilities: #include <chrono> #include <thread> std::this_thread::sleep_for(std::chrono::milliseconds(x)); Clear and readable, no more need to guess at what units the sleep() function takes.
One approach is to use a regular expression, like so: re=”^[0-9]+$” if ! [[ $yournumber =~ $re ]] ; then echo “error: Not a number” >&2; exit 1 fi If the value is not necessarily an integer, consider amending the regex appropriately; for instance: ^[0-9]+([.][0-9]+)?$ …or, to handle numbers with a sign: ^[+-]?[0-9]+([.][0-9]+)?$
Welcome to the wonderful world of portability… or rather the lack of it. Before we start analyzing these two options in detail and take a deeper look how different operating systems handle them, it should be noted that the BSD socket implementation is the mother of all socket implementations. Basically all other systems copied the … Read more
dos2unix is a commandline utility that will do this, or :%s/^M//g will if you use Ctrl–v Ctrl–m to input the ^M, or you can :set ff=unix and Vim will do it for you. There is documentation on the fileformat setting, and the Vim wiki has a comprehensive page on line ending conversions. Alternately, if you … Read more
This should work: date +%s
The reason this occurs is because bash actually expands the asterisk to every matching file, producing a very long command line. Try this: find . -name “*.pdf” -print0 | xargs -0 rm Warning: this is a recursive search and will find (and delete) files in subdirectories as well. Tack on -f to the rm command … Read more
You can do yes | cp -rf xxx yyy, but my gutfeeling says that if you do it as root – your .bashrc or .profile has an alias of cp to cp -i, most modern systems (primarily RH-derivatives) do that to root profiles. You can check existing aliases by running alias at the command prompt, … Read more
With ps or similar tools you will only get the amount of memory pages allocated by that process. This number is correct, but: does not reflect the actual amount of memory used by the application, only the amount of memory reserved for it can be misleading if pages are shared, for example by several threads … Read more
Turn on grep‘s line buffering mode when using BSD grep (FreeBSD, Mac OS X etc.) tail -f file | grep –line-buffered my_pattern It looks like a while ago –line-buffered didn’t matter for GNU grep (used on pretty much any Linux) as it flushed by default (YMMV for other Unix-likes such as SmartOS, AIX or QNX). … Read more
Edit (by @dk14 as suggested by moderators and comments) WARNING: If you use credential.helper store from the answer, your password is going to be stored completely unencrypted (“as is”) at ~/.git-credentials. Please consult the comments section below or the answers from the “Linked” section, especially if your employer has zero tolerance for security issues. Even … Read more