Linux hints
List Processes
ps (processes status) is a native Unix/Linux utility for viewing information concerning a selection of running processes on a system
Command for listing all of the processes in a user friendly tree hierarchy.
ps auxf
a = show processes for all users
u = outputs using the "user-oriented" format, which gives more columns, including the user id and CPU/memory usage.
x = also show processes not attached to a terminal
f = ASCII art process hierarchy (forest).
Version
cat /etc/os-release
File Content
Number of lines in file
wc -l <filename>
Disk Size
DU
The du command is very useful to track down disk space hogs. It is useful to find out the names of directories and files that consume large amounts of space on a disk.
Find top files in the current and subdirectories
find -type f -exec du -Sh {} + | sort -rh | head -n 5
Display tree directory with the estimated sizes
tree --du -h
DF
Shows the amount of disk space used and available on Linux file systems.
df -H
Remote Copy
TO
scp {local_directory/file} {username}@{host}:{remote_directory}
FROM
scp {username}@{host}:{remote_directory}/{file} {local_directory}
GZIP
gzip {file}
gunzip {zipped_file}
Distributions
Alpine
Alpine Linux is an independent, non-commercial, general purpose Linux distribution designed for power users who appreciate security, simplicity and resource efficiency. It is built around musl libc and busybox. A container requires no more than 8 MB and a minimal installation to disk requires around 130 MB of storage.
Install software
Alpine uses its own package management system, apk-tools, which originally was a collection of shell scripts but was later rewritten in C. Alpine currently contains most commonly used packages such as GNOME, Xfce, Firefox, and others.
apk add
In case of an error
bash-4.4# apk add postgresql-client
WARNING: Ignoring APKINDEX.70c88391.tar.gz: No such file or directory
WARNING: Ignoring APKINDEX.5022a8a2.tar.gz: No such file or directory
ERROR: unsatisfiable constraints:
postgresql-client (missing):
required by: world[postgresql-client]
run with –update-cache command
apk add --update-cache command
Sources:
30 Useful ‘ps Command’ Examples for Linux Process Monitoring
TecMint - How to Find Out Top Directories and Files (Disk Space) in Linux
