install and uninstall rpm packages under Linux

Install a given rpm package. –force overwrites the package if it is already installed

rpm -i --force myrpm.rpm 

List installed rpm packages (-qa: query all)

rpm -qa

Find the exact name of an installed rpm package

rpm -qa | grep java

Uninstall the Java package in one step by using a subcommand.

rpm -e `rpm -qa | grep $PKG`

uninstall package without using scripts. This is useful if the package won’t uninstall when trying to uninstall it normally. Afterwards the package is not listed anymore by rpm -qa

rpm -e mypackage --noscripts

Convert Windows files to Unix by removing carriage returns (batch, bulk)

If you edit files under Windows and then move them to a Linux server, you may encounter the problem that Windows uses \r\n as newline while Linux just uses \n. To remove the carriage return in all files ending on .sh or .SPEC use the following command:

 find . -type f \( -name "*.sh" -o -name "*.SPEC" \) -exec sh -c "tr -d '\15\32' {} > {}.nn" \; 

For each file found by find, a shell is executed, which again executes the tr command to drop \r. The tr command is given the current file via the {} parameter. The output of the tr command is redirected from the standard output to a new file that consists of the current file’s name ({} again} plus the ending .nn.