Problem scenario
You run this command: sudo ls -lh /dev

You see output like this:

crw-rw—- 1 root tty 7, 131 Dec 23 19:20 vcsa3
crw-rw—- 1 root tty 7, 132 Dec 23 19:20 vcsa4
crw-rw—- 1 root tty 7, 133 Dec 23 19:20 vcsa5
crw-rw—- 1 root tty 7, 134 Dec 23 19:20 vcsa6

You want to know if the “c” is a link to another file or something else.

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Continue reading “What Type of Linux File Has Permissions That Are Symbolized with a “c”?”

Problem scenario
You want to substitute the nth word of a given line. How do you use awk to accomplish this?

Solution
Let’s assume the lines that you want to modify are in goodfile.txt. To replace the fourth item in the string with “new string”, run this command:

cat goodfile.txt | awk ‘{ print $1 ” ” $2 ” ” $3 ” new string ” $5 ” ” $6 }’

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Continue reading “How Do You Use awk for String Replacement of Lines where the Word to Be Replaced Is in the Same Position?”

You have one of the following two problems:

Problem scenario #1
Your GCP startup-script is not working. You do not know why. What should you do?

OR

Problem scenario #2
A bash script is not working. It stops executing after a certain line. There are few clues as to what is wrong.

Solution
Did you copy the script from a webpage?

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Continue reading “How Do You Troubleshoot a Bash Script Copied from the Internet?”

Problem scenario
You want to delete all the files (but not subdirectories) that are less than 10 KB in Linux’s /tmp/ directory. How do you do this?

Solution
Run this command: find /tmp/ -maxdepth 1 -type f -size -10k -ls | awk ‘{print $NF}’ | rm -rf

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Continue reading “How Do You Delete Files from a Directory That Are Smaller Than 10 KB with a Bash Command?”