Common Linux Commands
less
cat
more
vi
cd
ls
ln {oldfile} {newfile} (create a file link)
mv [options] source dest (Remove and rename files or directories)
-b (backup files that are about to be overwritten)
-i (interactive mode)
mkdir [directoryName]
rmdir [directoryName]
rm -rf [directoryName] //force delete recursively without prompting
tail -1000f access_log //use Ctrl+C to break it out.
touch
cp [options] source dest
-b, -i (same as above)
-p (preserve the original file's ownership, group, permissions and timestamp (the meta info)
chmod{u|g|o|a} {+|-} {r|w|x} {filename}
chown
find managmentconsole/ -name "MCExcep*"
find . -name CVS -exec ls Tag {} \;
grep [options] pattern filenames
-i (case sensitive)
-n (show the line# along with the matched line)
-v (invert match, find all lines that do NOT match)
-w (match entire words)
grep -R "a string" /etc/*
pwd //Display the present working directory
which //Display a program's executable path
whoami
whereis //Locates binaries and manual pages for the ls command.---------------------------------------------------------
System Command
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date //check timestamp
df //Available free disk space
ps
pstree
kill
man (View manual pages)
mail (Read your email)
mount
umount
printtool (Use to set up printer)
top (memory usage profile)
su/changeme (do things as superuser), exit (back to original user)
passwd
nohup ./start.sh & //start a program remotely in the background
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Establish Cron job
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crontab -e Edit your crontab file, or create one if it doesn't already exist.
crontab -l Display your crontab file.
crontab -r Remove your crontab file.
crontab -v Display the last time you edited your crontab file. (This option is only available on a few systems.)
* * * * * command to be executed
- - - - -
| | | | |
| | | | +----- day of week (0 - 6) (Sunday=0)
| | | +------- month (1 - 12)
| | +--------- day of month (1 - 31)
| +----------- hour (0 - 23)
+------------- min (0 - 59)
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Process handling
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CTRL+Z (suspend the job -- stop running, instead of '&' that job is still running in background)
>> [1]+ Stopped ls -R | more (+ mean the lastest job that got suspended, and you can suspend >1)
fg (it will bring back the latest job got suspended)
fg # (selectively bring back a job)
fg %find (bring back a process that start with "find" string - find command process)
fg %?usr (bring back a process that contains 'usr' in its command path)
bg %[number] (send the job 1 to background as &)
bg %[string]
kill %[number]
kill %[string]
jobs (to list out all the suspended jobs)
[1] Stopped ls -R /usr >> output
[2]+ Stopped find / -print > output.find
[3] Stopped ls -R /var >> output
[4]- Stopped ls -R >> output
[5] Running ls -R /var >> output &Job 2 now has + sign following it (latest job that suspended)
Job 4 has the minus sign (2nd last job suspended)
Job 5 is running in the background still (notice & sign)
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Compression/ Decompression of files
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Compressed files use less disk space and download faster than large,
uncompressed files. You can compress Linux files with the open-source
compression tool Gzip or with Zip (for file exchange with non-Linux user), which is recognized by most operating systems. You use Tar to achive files into single tar but it doesn’t do compression automatically.gzip filename.ext (compress a file and saved as filename.ext.gz)
gzip filename.gz file1 file2 mydir/ (compress to a gz file)
gunzip filename.ext.gz (expand the compressed file)
gzip -d xxx.tar.gz (Uncompress the .gz file)
zip -r filename.zip files (compress a file with zip)
unzip filename.zip (expand the compressed zip file)
unzip -l xxx.zip (list all the file out)
zip -d br_MgmtConsole3Dev.zip \*\target\* (delete everything with target in the path inside the zip)
tar -cvf xxx.tar [files or directories] (create tar)
tar -czvf xxx.tgz mydir/ (create tgz = tar.gz)
tar -xvf xxx.tar (untar)
tar -xzvf xxx.tgz (untar tgz)
tar -tvf xxx.tar (to list the contents of a tar file)
jar cf abc.jar com com2 ... (jar the directory recursively with space separated to the abc.jar)
jar xf abc.jar (Extract)
jar -tvf xxx.war (examine what is inside it)
jar cf cocoon-2.1.5.1.war webapp (create a war file from the webapp directory)
jar tvf weblogic.jar |grep bcel (do the search on the output)
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Networking
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Here is good linux networking guide for your reference.
Host file location: /etc/hostsifconfig (check your box's IP address)
ping (send ICMP ECHO_REQUEST packet to the specific host. If the host is alive, an ICMP packet will be sent back)
traceroute www.justproposed.com (It displays each host that a packet travels through)
host www.justproposed.com (return IP of JP)
nslookup 64.102.102.32 (return DNS name of the IP)
netstat (port scan in the localbox)
finger
telnet <hostname> <port> (quick test to see if a remote service is up or not)
dig @192.168.1.254 www.slackware.com mx (“@192.168.1.254” specifies the
dns server to use. “www.slackware.com” is the domain name I am
performing a lookup on, and “mx” is the type of lookup I am performing.
The above query tells me that e-mail to www.slackware.com will instead
be sent to mail.slackware.com for delivery.)
ssh
sftp hostname (then you can do "put filename")
scp filename remote_host:directory (Copy a file from current directory to remote directory /home/honr). eg. scp filename1 honr@appden11.xyz.net:/home/honr
scp honr@appden11.xzy.net:/home/honr/filename . (Copy a file from remote directory to my current directory)
wget <url> (download a file from the url - http or ftp)
wget –recursive <url> (download the whole site)
ftp <url> (connect to ftp server and you can issue command once connected)
curl -I www.google.com/”>http://www.google.com (Get the HTTP Header)
