The grep command is used to search for text, or lines containing certain words or strings of words. Stackoverflow, techonthenet, linux are a few sites that tell more about this command
Use the 'grep' command
PS -eaf|grep defunct
There isn't a concept of a 'default' shell in Unix; you may have a login shell specified by the system administrator for use when you log in. Although it isn't a fool-proof way to find your shell, you could use the command: echo $SHELL or use the 'finger' command to see what your default login shell environment is. You could also 'grep' for your information in the password file because the last field is your login environment shell.
A Unix filter is a command pattern that allows the output of one command to be "piped" into the input of the next command. Commands like 'ls' which list a directory are not filters since they only generate output. Filter examples are grep, sed, sort, uniq, awk. Commands in Unix are usually filters unless they only create output, like 'ls', 'vi', etc.
Use the 'grep' command.
Use the 'grep' family of commands to search for string pattern matches in multiple files.
'grep' searches a file for lines which match a given regular expression.
grep '\<h.*o\>'
I think you mean the regular expression tool "grep".
The grep function in Perl is the command-line function which can be used to search in a data set for lines which match a regular expression. The grep function is essentially a tool that can be used to search for particular information within the data.
Use the "-i" argument See 'man grep' for more information
You would use a pipe. For example. ls | grep cool The output of ls(the list of files in your current directory) is given to grep. Grep then finds and prints file names that include the word cool in them.