دستورهای ضروری لینوکس که هر برنامه‌نویسی باید بداند

pwd                 # where am I?
ls -lah             # list everything: long format, hidden files, human-readable sizes
cd /var/log         # go to an absolute path
cd ..               # up one level
cd -                # jump back to the previous directory
cd                  # go home (same as cd ~)

mkdir -p projects/blog/src     # create nested directories in one go
touch notes.txt                # create an empty file (or update its timestamp)
cp config.yml config.yml.bak   # copy a file
cp -r src/ backup/             # copy a directory recursively
mv draft.md posts/final.md     # move and/or rename
rm old.log                     # delete a file
rm -r build/                   # delete a directory and everything in it

cat package.json        # print a whole (short) file
less /var/log/syslog    # scroll through a long file (q to quit, / to search)
head -n 20 app.log      # first 20 lines
tail -n 50 app.log      # last 50 lines
tail -f app.log         # follow new lines as they're written, great for live logs

grep "ERROR" app.log            # lines containing ERROR
grep -i "timeout" app.log       # case-insensitive
grep -rn "TODO" src/            # search recursively, show line numbers
grep -v "DEBUG" app.log         # lines that do NOT match
grep -c "404" access.log        # count matching lines

find . -name "*.py"                       # all Python files below the current directory
find /var/log -name "*.log" -mtime -1     # .log files modified in the last 24 hours
find . -type f -size +100M                # files bigger than 100 MB
find . -type d -name node_modules         # directories named node_modules

# Top 5 IP addresses hitting your web server
cut -d' ' -f1 access.log | sort | uniq -c | sort -rn | head -5

ls -la > files.txt          # write output to a file (overwrites it)
echo "done" >> build.log    # append to a file
npm test > test.log 2>&1    # capture both normal output and errors
wc -l < data.csv            # use a file as input: counts its lines

-rwxr-xr-- 1 deploy www-data 2048 Oct 12 09:30 deploy.sh

chmod +x deploy.sh                              # make a script executable
chmod 644 index.html                            # owner: read/write, everyone else: read-only
chmod 755 scripts/                              # owner: full access, everyone else: read and enter
sudo chown -R www-data:www-data /var/www/site   # change owner and group recursively

ps aux | grep node          # find running node processes
top                         # live view of CPU and memory use (q to quit)
kill 12345                  # politely ask process 12345 to stop
kill -9 12345               # force it to stop (last resort)

df -h               # free disk space per filesystem
du -sh *            # size of each item in the current directory
du -sh * | sort -h  # ...sorted from smallest to largest
free -h             # memory usage

curl https://example.com          # fetch a page
curl -I https://example.com       # headers only: check status codes and caching
curl -X POST -H "Content-Type: application/json" \
     -d '{"name": "Ada"}' https://httpbin.org/post
sudo ss -tlnp                     # which programs are listening on which ports
ping -c 4 example.com             # is the host reachable?

ssh user@203.0.113.10                                 # log in to a server
scp report.pdf user@203.0.113.10:~/                   # copy a file to it
rsync -avz ./site/ user@203.0.113.10:/var/www/site/   # sync a whole directory efficiently

man grep                 # the full manual (q to quit)
grep --help              # a quick summary of options
history | grep docker    # find that command you ran last week