I am only fairly new to unix, so i have a question about grep.... i use the grep command at work to search for particular records. i use the grep command as "grep <criteria> <filename>". i know it is possible to search for two criterias in the one command, but am unsure how to do it. i need to know how to, for example, search for criteria A AND criteria B in the one file in the one one command. can someone please explain to me how i can do this. thanks in advance

If you want to select records which satisfies the criteria A OR B : grep 'criteria A|criteria B' input_file If you want to select records which satisfies the criteria A AND B : grep 'criteria A' input_file | grep 'criteria B' Jean-Pierre.

" If you want to select records which satisfies the criteria A OR B : grep 'criteria A|criteria B' input_file " No: grep -E or egrep 'criteria A|criteria B' input_file "if you want to select records which satisfies the criteria A AND B : grep 'criteria A' input_file | grep 'criteria B' " No: grep 'criteria B' $(grep -l 'criteria A' input_file)

No: grep -E or egrep 'criteria A|criteria B' input_file That's right No: grep 'criteria B' $(grep -l 'criteria A' input_file) No, your command select records matching 'criteria B' from files which contains a record matching 'criteria B'. Records matching 'criteria A' are not displayed. Displayed records match 'criteria B', not criteria A AND B. Jean-Pierre.