Essential Linux Command-Line Tricks for Everyday Tasks

Linux users often need quick, reliable ways to verify files, locate resources, manage processes, and view logs. This article compiles a set of practical command-line tricks to streamline these tasks.

1. Verify File Checksums

To ensure file integrity after copying or transferring, generate and compare checksums using tools such as md5sum, cksum, and sum:

md5sum file_name
cksum file_name
sum -r file_name   # system V algorithm
sum -s file_name   # BSD algorithm

Example with test.txt:

MD5: md5sum test.txt CRC: cksum test.txt SUM (system V): sum -r test.txt SUM (BSD):

sum -s test.txt

2. Locate Files Quickly

(1) locate

locate

searches a prebuilt database ( /var/lib/slocate) and is usually faster than find. Install it if missing (e.g., apt-get update && apt-get install mlocate on Ubuntu).

locate file_name

(2) find

Use find for real‑time filesystem searches with criteria such as name, type, size, or owner:

find / -name stdio.h

3. Command‑Line Editing Shortcuts

When a long, erroneous command line is entered, use these shortcuts instead of repeatedly pressing Backspace: Ctrl+U – delete everything before the cursor. Ctrl+K – delete everything after the cursor. Ctrl+A – move cursor to the beginning of the line. Ctrl+E – move cursor to the end of the line.

4. View Process IDs

pidof process_name

Example output is shown in the accompanying screenshot.

5. Monitor Specific Processes

Use top -p $(pidof kcalc) to display only the desired process. Multiple processes can be monitored simultaneously:

top -p $(pidof kcalc) -p $(pidof test_x86)

6. Terminate Processes

(1) kill

kill -9 process_pid

(2) killall

killall process_name

7. Save Terminal Output to a File

(1) tee

executable_file | tee log_file

(2) script

Start recording: script log.txt Stop recording with exit.

(3) Terminal tools with built‑in logging (e.g., Terminator)

8. Check Dynamic Library Dependencies

ldd executable_file

9. Inspect ELF File Headers

Use readelf -h elf_file to view architecture and other metadata. The file command also provides a quick summary.

10. View Text Files Efficiently

cat

– simple concatenation; cat -n adds line numbers. tac – display file from bottom to top. more – paginated view with progress percentage. less – flexible pagination (PgUp/PgDn) without progress bar. head – show the first n lines (e.g., head -n 20 /etc/profile). tail – show the last n lines. nl – display file with line numbers, similar to cat -n.

11. Set LD_LIBRARY_PATH

export LD_LIBRARY_PATH=./:$LD_LIBRARY_PATH

This adds the current directory to the library search path for dynamic linking.

These tips collectively help Linux users perform routine diagnostics, file handling, and process management more efficiently.