Revised Answer (Feb 12, 2014) the_world_is_flat=true # …do something interesting… if [ “$the_world_is_flat” = true ] ; then echo ‘Be careful not to fall off!’ fi Original Answer Caveats: https://stackoverflow.com/a/21210966/89391 the_world_is_flat=true # …do something interesting… if $the_world_is_flat ; then echo ‘Be careful not to fall off!’ fi From: Using boolean variables in Bash The reason … Read more
If Machine A is a Windows box, you can use Plink (part of PuTTY) with the -m parameter, and it will execute the local script on the remote server. plink root@MachineB -m local_script.sh If Machine A is a Unix-based system, you can use: ssh root@MachineB ‘bash -s’ < local_script.sh You shouldn’t have to copy the … Read more
In bash (>=4.2) it is preferable to use printf’s built-in date formatter (part of bash) rather than the external date (usually GNU date). As such: # put current date as yyyy-mm-dd in $date # -1 -> explicit current date, bash >=4.3 defaults to current time if not provided # -2 -> start time for shell … Read more
None of these solutions worked for me. Instead, I elaborate on @Martin v. Löwis ‘s mention of setting a config file for SSH. SSH will look for the user’s ~/.ssh/config file. I have mine setup as: Host gitserv Hostname remote.server.com IdentityFile ~/.ssh/id_rsa.github IdentitiesOnly yes # see NOTES below And I add a remote git repository: … Read more
The are various ways: POSIX standard tr $ echo “$a” | tr ‘[:upper:]’ ‘[:lower:]’ hi all AWK $ echo “$a” | awk ‘{print tolower($0)}’ hi all Non-POSIX You may run into portability issues with the following examples: Bash 4.0 $ echo “${a,,}” hi all sed $ echo “$a” | sed -e ‘s/\(.*\)/\L\1/’ hi all # … Read more
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
The simplest and most widely available method to get user input at a shell prompt is the read command. The best way to illustrate its use is a simple demonstration: while true; do read -p “Do you wish to install this program? ” yn case $yn in [Yy]* ) make install; break;; [Nn]* ) exit;; … Read more
It is: if [ $# -eq 0 ] then echo “No arguments supplied” fi The $# variable will tell you the number of input arguments the script was passed. Or you can check if an argument is an empty string or not like: if [ -z “$1” ] then echo “No argument supplied” fi The … Read more
If -prune doesn’t work for you, this will: find -name “*.js” -not -path “./directory/*” Caveat: requires traversing all of the unwanted directories.
Try: find . -name ‘*.php’ | xargs wc -l or (when file names include special characters such as spaces) find . -name ‘*.php’ | sed ‘s/.*/”&”/’ | xargs wc -l The SLOCCount tool may help as well. It will give an accurate source lines of code count for whatever hierarchy you point it at, as … Read more