You have a linux box? Then you probably know how to spend time when you have nothing to do. I know that most linux users when they have nothing to do, spend time reading mans or looking in the "bin" folders such as /usr/bin or /bin for a new discovery. The "bin" folders are gold mines for those who want to know more or to find new commands. Since I was at the university, my way is very simple: I open a terminal, I write a random letter and I push the "TAB" key twice and a list of all commands which start with that letter is displayed.
Just an example: If I write "t" and I push the "TAB" key twice, on my system, come up 139 commands which start with the letter "t". The first command in the list is "tac". Did you know what the "tac" command does? "tac" is the opposite of "cat". It's easy to see that it is the opposite of "cat", isn't it? "cat" reads a file from top to bottom, whereas "tac" reads upwards.
As you see with "tac" the last line in the file is the first displayed and the first is the last shown.
"tac" is very useful, specialy to read log files when the last entries are more important than the first.
Conclusion:
The "bin" folders are gold mines. Check it your self and never get bored with *nix.
Just an example: If I write "t" and I push the "TAB" key twice, on my system, come up 139 commands which start with the letter "t". The first command in the list is "tac". Did you know what the "tac" command does? "tac" is the opposite of "cat". It's easy to see that it is the opposite of "cat", isn't it? "cat" reads a file from top to bottom, whereas "tac" reads upwards.
[root@mylinux ~]# echo "1- Hi, this is the first line" > toto.txt
[root@mylinux ~]# echo "2- Hi, this is the second line" >> toto.txt
[root@mylinux ~]# echo "3- Hi, this is the third line" >> toto.txt
[root@mylinux ~]# cat toto.txt
1- Hi, this is the first line
2- Hi, this is the second line
3- Hi, this is the third line
[root@mylinux ~]# tac toto.txt
3- Hi, this is the third line
2- Hi, this is the second line
1- Hi, this is the first line
As you see with "tac" the last line in the file is the first displayed and the first is the last shown.
"tac" is very useful, specialy to read log files when the last entries are more important than the first.
Conclusion:
The "bin" folders are gold mines. Check it your self and never get bored with *nix.