On 06/08/2010 10:54 AM, Kevin J. Cummings wrote: > On 06/08/2010 12:40 PM, Kaushal Shriyan wrote: > >> Hi, >> >> can someone explain me about the usage of grep , fgrep and egrep >> with examples. >> In what contexts i should use which. >> > The grep man page explains it well enough: > ... All well and good, but: Once upon a time ... fgrep used to equate to fast grep, or file grep -- both start with f so it was easy to remember. Want to get a subset of two lists? fgrep -f file1 file2 will produce a subset existing in file2 from file1. Want to search for more than one string, or using a complex regular expression? egrep "this|that|the other" file1 That was the difference, and for us old guys, they still work that way, even though there is really only one grep program. How you envoke it sets it to default to the other behavior, or the command line switch does the same, as explained. For new guys, learn to use grep always, but us old guys are glad the links to the old versions are still there. :) -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
