Commands by ysangkok (5)

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Print only the odd lines of a file
NR%2 == 1 on odd lines and 0 on even lines

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Do a search-and-replace in a file after making a backup

Kill multiple instances of a running process

get stdout to variable and stdout at sametime
Sometimes you want to write the script output to stdout but you need to send it to email. If you use: $ var="$( ls / )"; $ echo -e "$var"; works but, you need to wait the script terminate to bufferize then print the output var; With this way, you can use/work/print the output before the variable receive all the output content, then after it you can use the variable for anything else, like send email.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

mount an iso
mounts an ISO file to a directory on the target file system

print a file on a single line
Example: you have a package.txt you want to install on a system. Instead of this: cat package.txt package1 package2 package3 You want it to cat out on one line so you can print "yum install package1 package2 package3"

cd to (or operate on) a file across parallel directories
This is useful for quickly jumping around branches in a file system, or operating on a parellel file. This is tested in bash. cd to (substitute in PWD, a for b) where PWD is the bash environmental variable for the "working directory"

Substrings a variable
substrings a variable starting at position. If no offset given prints rest of the line


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