Unix Commands
1)nohup scriptname & - Automatically runs the jobs in the background even after exit
2)disown -h jobID--runs the jobs even if you exit from the terminal
disown -r -deletes all the running jobs
disown jobid -Removes specific running active job
disown -a --deletes or removes all the active jobs
3)exit or CTRL+D - exit from the terminal
4)ps aux ... list the status of all jobs by process identifier (PID)
PS -A --Process of All users
PS -u Vivek --Process of Single users
5) jobs -l -displays all the running and non running jobs
6)rm -rf foo/bar/baz-- removing the present directory
rmdir name_of_directory--remove directories if empty
rmdir -p foo/bar/baz--removing the present directory and its parent directories even if files exists
rm filename - Contents are recoverble
rm -Rf filename - Force remove -- contents are not recoverable
7)ls -l ... list all files in the current working directory, along with each file's permission, owner, size in bytes and date of last modification.
8) ctrl c Abort the program currently running
ctrl z Suspend the program currently running (use fg or bg to resume the program in the foreground or background, respectively)
9)KILL -15 <>--CLEANUP operations and Uses SIGTERM signal
10)KILL -9 <> -No CLEANUP operations and Uses SIGKILL signal
11)shred option filename -Overwriting the existing file multiple times and securely deleting the file
12)grep -a1 "fedora" sample.dat -- Print the serched line plus the above and below 1 lines
grep -A1 "fedora" sample.dat-- Print the serched line plus above the serached pattern one line
grep -B1 "fedora" sample.dat--Print the serched line plus below the serached pattern one line
13)set number -sets the line number in the unix sh file.
14)ls -F --list filenames with a special character at the end that tells you what kind of file it is ("/" for directory, "*" for unix executable, "@" for alias/symlink, etc)
15) grep -n "search string" filename will display the serched string and the line number
For Ex:
1ABC
2ABC
16)Hard Link -- ln filename pointerfilename--contains inode number of that file--Once deleted hardlink ,still the contents are visible
New File is not created and the file is just a mirror of the original file.
Cannot be used across filesystems ,Consumes extra space since new file
with new inode number is created.
Soft Link-- ln -s filename pointerfilename--contains file name to reference the file--
Once deleted softlink ,the contents are not visible
New File is not created and the file is just a mirror of the original file.
Can be used across filesystems,does not consume extra space since new file with new inode number is not created.
http://www.maxi-pedia.com/difference+between+symbolic+link+and+hard+link
ls -il --To see the hard and soft links in the particular directory
ls -F--When Soft link is created , the filename ends with @symbol which can be seen and identified as softlink by using this command.
1)nohup scriptname & - Automatically runs the jobs in the background even after exit
2)disown -h jobID--runs the jobs even if you exit from the terminal
disown -r -deletes all the running jobs
disown jobid -Removes specific running active job
disown -a --deletes or removes all the active jobs
3)exit or CTRL+D - exit from the terminal
4)ps aux ... list the status of all jobs by process identifier (PID)
PS -A --Process of All users
PS -u Vivek --Process of Single users
5) jobs -l -displays all the running and non running jobs
6)rm -rf foo/bar/baz-- removing the present directory
rmdir name_of_directory--remove directories if empty
rmdir -p foo/bar/baz--removing the present directory and its parent directories even if files exists
rm filename - Contents are recoverble
rm -Rf filename - Force remove -- contents are not recoverable
7)ls -l ... list all files in the current working directory, along with each file's permission, owner, size in bytes and date of last modification.
8)
9)KILL -15 <
10)KILL -9 <
11)shred option filename -Overwriting the existing file multiple times and securely deleting the file
12)grep -a1 "fedora" sample.dat -- Print the serched line plus the above and below 1 lines
grep -A1 "fedora" sample.dat-- Print the serched line plus above the serached pattern one line
grep -B1 "fedora" sample.dat--Print the serched line plus below the serached pattern one line
13)set number -sets the line number in the unix sh file.
14)ls -F --list filenames with a special character at the end that tells you what kind of file it is ("/" for directory, "*" for unix executable, "@" for alias/symlink, etc)
15) grep -n "search string" filename will display the serched string and the line number
For Ex:
1ABC
2ABC
16)Hard Link -- ln filename pointerfilename--contains inode number of that file--Once deleted hardlink ,still the contents are visible
New File is not created and the file is just a mirror of the original file.
Cannot be used across filesystems ,Consumes extra space since new file
with new inode number is created.
Soft Link-- ln -s filename pointerfilename--contains file name to reference the file--
Once deleted softlink ,the contents are not visible
New File is not created and the file is just a mirror of the original file.
Can be used across filesystems,does not consume extra space since new file with new inode number is not created.
http://www.maxi-pedia.com/difference+between+symbolic+link+and+hard+link
ls -il --To see the hard and soft links in the particular directory
ls -F--When Soft link is created , the filename ends with @symbol which can be seen and identified as softlink by using this command.
