How to check if a Perl module is already installed?
Answer:
For example, to check if the DBI module is installed or not, use
perl -e 'use DBI;'
You will see error if not installed.
Dec 312009
Linux Ask!
Dec 312009
How to log console output to a file?
Answer:
Use the script command, example:
# script /tmp/output.txt (start logging, everything from now will go to output.txt)
# date
# exit (finish logging)
# cat /tmp/output.txt
Dec 312009
How to restart a frozen Linux System?
Answer:
Try the following two simple methods first:
- Hold down Ctrl+Alt+Backspace if you are in graphic mode
- if not work, then hold down "Ctrl+Alt+F1" to get into the shell and use the "reboot" command to reboot
If still not work, do the following:
- Hold down the Alt and SysRq (Print Screen) keys
- While holding those down, type the following in order: REISUB
- You computer will reboot now
Dec 312009
How to kill a running process by command?
Answer:
For example, if Firefox hang, in the command prompt, just type in
pkill firefox
Dec 312009
How to run multiple commands at once in Linux?
Answer:
You can separate the commands by a semicolon ;
e.g.
cat foo.txt; cat bar.txt
Two commands will be executed one by one.
However, if you want to execute a command if and only if previous command is executed successfully, then you can use && to separate them
e.g.
make && make install
So if make failed, make install will not be executed.
