What would be a more simplified description of file descriptors compared to Wikipedia’s? Why are they required? Say, take shell processes as an example and how does it apply for it? Does a process table contain more than one file descriptor. If yes, why? 12 s 12 In simple words, when you open a file, … Read more
When I have a diff, how can I colorize it so that it looks good? I want it for the command line, so please no GUI solutions. 16 s 16 Man pages for diff suggest no solution for colorization from within itself. Please consider using colordiff. It’s a wrapper around diff that produces the same … Read more
I keep getting ^M character in my vimrc and it breaks my configuration. 15 s 15 Unix uses 0xA for a newline character. Windows uses a combination of two characters: 0xD 0xA. 0xD is the carriage return character. ^M happens to be the way vim displays 0xD (0x0D = 13, M is the 13th letter … Read more
What is the command to make less display line numbers in the left column? 6 s 6
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I’m looking for the string foo= in text files in a directory tree. It’s on a common Linux machine, I have bash shell: grep -ircl “foo=” * In the directories are also many binary files which match “foo=”. As these results are not relevant and slow down the search, I want grep to skip searching … Read more
Recently I was asked this during a job interview. I was honest and said I knew how a symbolic link behaves and how to create one, but do not understand the use of a hard link and how it differs from a symbolic one. 25 s 25 Underneath the file system, files are represented by … Read more
Is there a command or an existing script that will let me view all of a *NIX system’s scheduled cron jobs at once? I’d like it to include all of the user crontabs, as well as /etc/crontab, and whatever’s in /etc/cron.d. It would also be nice to see the specific commands run by run-parts in … Read more
I set a passphrase when creating a new SSH key on my laptop. But, as I realise now, this is quite painful when you are trying to commit (Git and SVN) to a remote location over SSH many times in an hour. One way I can think of is, delete my SSH keys and create … Read more
$ time foo real 0m0.003s user 0m0.000s sys 0m0.004s $ What do real, user and sys mean in the output of time? Which one is meaningful when benchmarking my app? 8 Real, User and Sys process time statistics One of these things is not like the other. Real refers to actual elapsed time; User and … Read more
