List X random files from a directory
Is there a way to list a set of say, 30 random files from a directory using standard Linux commands? (in zsh)
shell
How to read an IP address backwards?
If we have this string (IP address): 192.168.1.1
recovering deleted file held open by apache?
Suppose an apache log file gets deleted but it’s held open by apache; then this is what I am doing:
sh startup files over ssh
I have some important commands I need to execute before any sh shell starts. This is required for passing SSH commands in the SSH command (ssh host somecommand) and other programs that run commands.
How can I time a pipe?
I want to time a command which consists of two separate commands with one piping output to another. For example, consider the two scripts below:
How does lookup in $PATH work under the hood?
There’re way too many articles/resources on the web that teaches people HOW to set the environment variable PATH so that they can use the short hand of java or python etc instead of the absolute path in command line interface.
Why is the array empty after the while loop?
I try to initialize an array in bash-4.2 next way: ring=() ls -las | tail -n +4 | while read line > do > ring+=("$line") > echo ${ring[-1]} > done 3924 -rw-r–r– 1 username group 4015716 Mar 23 15:14 script.jar 4 -rw-r–r– 1 username group 9 Feb 29 12:40 rec.lst 5541 -rw-r–r– 1 username group … Read more
Which shells support ANSI-C quoting? e.g. $’string’
I have a shell script that uses the following to print a green checkmark in its output:
Is field splitting and filename expansion turn off in RHS of variable assignment portable?
In most POSIX compliant shell like bash. ksh, dash, mksh, pdksh, when variable assignment occur, field splitting and filename expansion (and brace expansion if the shell supports) are not performed in RHS of assignment:
Where has the trailing newline char gone from my command substitution?
The following code best describes the situation. Why is the last line not outputting the trailing newline char? Each line’s output is shown in the comment. I’m using GNU bash, version 4.1.5