Posts
Linux Basics: Writing a Small Bash Script
A shell script saves a sequence of commands in a text file so you can run it again. This example accepts names as arguments and prints one greeting for each name. Use Bash on …
October 8, 2026
Linux Basics: Understanding File Permission Bits
Linux files have permission bits for their owner, their group, and everyone else. Practice with a file you create yourself before changing permissions on anything important. Use …
October 8, 2026
Linux Basics: Replacing Text with sed
sed can change text as it reads a file and write the result to the terminal. Start by previewing a replacement, then save it to a different file when the result looks right. Use …
October 8, 2026
Linux Basics: Quoting Text and Matching Filenames
Quotes control what Bash treats as one argument. Filename patterns let the shell select several files at once. Knowing the difference helps avoid surprises when names contain …
October 8, 2026
Linux Basics: Filtering and Totaling Fields with awk
awk is useful when you want to select records by a field value or calculate a total. It reads one record at a time, usually one line, and splits that record into fields. Use Bash …
October 8, 2026
Linux Basics: Using Bash Exit Status
A command reports an exit status separately from the text it prints. In Bash on Debian and Ubuntu, zero normally means success and a nonzero value signals another outcome. Checking …
October 6, 2026
Linux Basics: Sorting and Counting Text Lines
A list becomes easier to inspect when repeated entries are grouped and counted. Debian and Ubuntu include sort, uniq, and wc for this work. They read ordinary text files without …
October 6, 2026
Linux Basics: Selecting Text Fields with cut
When each line contains fields separated by the same character, cut can extract just the columns you need. It is useful for simple lists and tab-separated data on Debian and …
October 6, 2026
Linux Basics: Inspecting Network Addresses and Ports
Inspect the network configuration before changing settings. Debian and Ubuntu provide ip and ss through the iproute2 package. These read-only commands normally work without sudo. …
October 6, 2026
Linux Basics: Checking File Integrity with SHA-256
A checksum is a value calculated from a file’s bytes. On Debian and Ubuntu, sha256sum can record that value and check whether the file still matches it later. This is useful after …
October 6, 2026