From LedHed's Wiki
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'''Tips -N- Tricks''' | '''Tips -N- Tricks''' | ||
| + | == Truncating a File == | ||
| + | If you want to empty a file quickly (like purging a log file) then run the following command: | ||
| + | :> filename | ||
== Search command history == | == Search command history == | ||
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To re-enable it use this command: | To re-enable it use this command: | ||
swapon -a | swapon -a | ||
| + | |||
| + | == Run a command as a different User == | ||
| + | su <SOME_OTHER_USER> | ||
| + | or Run as a user that doesn't have shell access (Like the 'www' account). | ||
| + | su -m www -c "run some command here" | ||
| + | Note: The -c option is used to run a single command. | ||
| + | |||
| + | |||
| + | |||
| + | |||
| + | == RPM's == | ||
| + | RedHat based distributions use RPM's short for Redhat Package Manager. | ||
| + | To view a list of installed RPMS: | ||
| + | rpm -qa | ||
| + | To look for a specific installed package: | ||
| + | rpm -qa | grep 'package_name' | ||
| + | |||
| + | To view the contents of a RPM | ||
| + | rpm -qpil /path/to/package.rpm | ||
| + | |||
| + | Common Sqitches: | ||
| + | -i Install<br> | ||
| + | -U Upgrade<br> | ||
| + | -v verbose<br> | ||
| + | -h Display Hash mark progress bar<br> | ||
| + | -e erase<br> | ||
| + | --force forces an erase or upgrade<br> | ||
[[Category:Linux]] | [[Category:Linux]] | ||
Latest revision as of 05:53, 4 June 2012
Tips -N- Tricks
Contents
Truncating a File
If you want to empty a file quickly (like purging a log file) then run the following command:
:> filename
Search command history
grep -i 'SearchStringHere' ~/.bash_history
View Log Continuously
tail -f /path/to/log/filename
or
Filter a continuous log for a specific entry
tail -f /path/to/log/filename | grep -i 'FilterStringHere'
Dump a .conf file to a new file without the comments (#)
grep -v '#' file.conf > newfile.conf
Disable/Enable Swap
To disable all swap space in Linux use this command:
swapoff -a
To re-enable it use this command:
swapon -a
Run a command as a different User
su <SOME_OTHER_USER>
or Run as a user that doesn't have shell access (Like the 'www' account).
su -m www -c "run some command here"
Note: The -c option is used to run a single command.
RPM's
RedHat based distributions use RPM's short for Redhat Package Manager. To view a list of installed RPMS:
rpm -qa
To look for a specific installed package:
rpm -qa | grep 'package_name'
To view the contents of a RPM
rpm -qpil /path/to/package.rpm
Common Sqitches:
-i Install
-U Upgrade
-v verbose
-h Display Hash mark progress bar
-e erase
--force forces an erase or upgrade