linux commands for every web developer/Software engineer

scp – Linux command line tool to copy files over ssh

scp [[user@]from-host:]source-file [[user@]to-host:][destination-file]

scp  abc.TXT root@10.215.3.150:/home/user/xyz.TXT


from-host
Is the name or IP of the host where the source file is, this can be omitted if the from-host is the host where you are actually issuing the command
user
Is the user which have the right to access the file and directory that is supposed to be copied in the cas of the from-host and the user who has the rights to write in the to-host
source-file
Is the file or files that are going to be copied to the destination host, it can be a directory but in that case you need to specify the -r option to copy the contents of the directory
destination-file
Is the name that the copied file is going to take in the to-host, if none is given all copied files are going to maintain its names

Copy Multiple fies

scp root@192.168.168.052:/home/ftp-124/5656/$dir/\{abc.txt,def.txt,ghi.txt\} root@192.168.168.053:/home/shahzeb

Restart MySql Ubuntu

To restart Apache2 on Ubuntu, we enter the following command in a terminal such as bash:

restart mysql

service mysql start


Restart Apache2 Ubuntu

To restart Apache2 on Ubuntu, we enter the following command in a terminal such as bash:

/etc/init.d/apache2 restart

Of course, you most likely will need to be the superuser to do that so you might need to enter the following command and then your password when requested:

sudo /etc/init.d/apache2 restart

Pointer

use pointer to acees the variable within a variable directly like

 foo=bar
 name=foo
 echo ${!name}
Result : bar

grep command: 

grep command usually interpet “|” as “AND” sign but you can use the same “|” for “OR” sign

for example

zgrep “^2012-06-05″ /var/path/to/file/abc12346-12-06* | grep -E ‘3003300356|3003301763|3008203898|3008202542|3008226266|3003404159′

zgrep = grep for gzipped files