File Commands:
1
ls
Directory listing
2
ls -al
Formatted listing with hidden files
3
ls -lt
Sorting the Formatted listing by time modification
4
cd dir
Change directory to dir
5
cd
Change to home directory
6
pwd
Show current working directory
7
mkdir dir
Creating a directory dir
8
cat >file
Places the standard input into the file
9
more file
Output the contents of the file
10
head file
Output the first 10 lines of the file
11
tail file
Output the last 10 lines of the file
12
tail -f file
Output the contents of file as it grows,starting with the last 10 lines
13
touch file
Create or update file
14
rm file
Deleting the file
15
rm -r dir
Deleting the directory
16
rm -f file
Force to remove the file
17
rm -rf dir
Force to remove the directory dir
18
cp file1 file2
Copy the contents of file1 to file2
19
cp -r dir1 dir2
Copy dir1 to dir2;create dir2 if not present
20
mv file1 file2
Rename or move file1 to file2,if file2 is an existing directory
21
ln -s file link
Create symbolic link link to file
Process management :
1
ps
To display the currently working processes
2
top
Display all running process
3
kill pid
Kill the process with given pid
4
killall proc
Kill all the process named proc
5
pkill pattern
Will kill all processes matching the pattern
6
bg
List stopped or background jobs,resume a stopped job in the background
7
fg
Brings the most recent job to foreground
8
fg n
Brings job n to the foreground
File permission:
1. chmod octal file Change the permission of file to octal,which can be found separately for user,group,world by adding,
• 4-read(r)
• 2-write(w)
• 1-execute(x)
Searching:
1
grep pattern file
Search for pattern in file
2
grep -r pattern dir
Search recursively for pattern in dir
3
command | grep pattern
Search pattern in the output of a command
4
locate file
Find all instances of file
5
find . -name filename
Searches in the current directory (represented by a period) and below it, for files and directories with names starting with filename
6
pgrep pattern
Searches for all the named processes , that matches with the pattern and, by default, returns their ID.
System Info:
| 1 | date | Show the current date and time |
| 2 | cal | Show this month's calender |
| 3 | uptime | Show current uptime |
| 4 | w | Display who is on line |
| 5 | whoami | Who you are logged in as |
| 6 | finger user | Display information about user |
| 7 | uname -a | Show kernel information |
| 8 | cat /proc/cpuinfo | Cpu information |
| 9 | cat proc/meminfo | Memory information |
| 10 | man command | Show the manual for command |
| 11 | df | Show the disk usage |
| 12 | du | Show directory space usage |
| 13 | free | Show memory and swap usage |
| 14 | which app | Show which applications will be run by default |
| 15 | whereis app | Show possible locations of app |
Compression:
| 1 | tar cf file.tar file | Create tar named file.tar containing file |
| 2 | tar xf file.tar | Extract the files from file.tar |
| 3 | tar czf file.tar.gz files | Create a tar with Gzip compression |
| 4 | tar xzf file.tar.gz | Extract a tar using Gzip |
| 5 | tar cjf file.tar.bz2 | Create tar with Bzip2 compression |
| 6 | tar xjf file.tar.bz2 | Extract a tar using Bzip2 |
| 7 | gzip file | Compresses file and renames it to file.gz |
| 8 | gzip -d file.gz | Decompresses file.gz back to file |
Network:
| 1 | ping host | Ping host and output results |
| 2 | whois domain | Get whois information for domains |
| 3 | dig domain | Get DNS information for domain |
| 4 | dig -x host | Reverse lookup host |
| 5 | wget file | Download file |
| 6 | wget -c file | Continue a stopped download |
Shortcuts:
1
ctrl+c
Halts the current command
2
ctrl+z
Stops the current command, resume with fg in the foreground or bg in the background
3
ctrl+d
Logout the current session, similar to exit
4
ctrl+w
Erases one word in the current line
5
ctrl+u
Erases the whole line
6
ctrl+r
Type to bring up a recent command
7
!!
Repeats the last command
8
exit
Logout the current session
Tags
Unix/Linux