Hdi2u S21

Grep

• grep stands for "global regular expression print"
• you use this command to search for text patterns in a file, for example, Linux's mini-dicitonary.

grep "adge" /usr/share/dict/words

• regular expressions are different and more powerful than wildcard characters
• made of special symbols which designate type of characters.
• grep requires a regular expression pattern as a parameter, and prints all the lines in a file containing that pattern.
• grep is especially useful in combination with pipes as you can filter the results of other commands.
• For example, perhaps you only want to see only the information in an EMBL file relating to the origin of the

sequence, that is, the DE line?

Exercise

• While in the hdi2u_files directory, type the command:

grep "DE" hsy14768.embl

What is this command doing?