The grep command has a number of options that control its behavior. Not all versions of UNIX support exactly the same options, so be sure to check your man pages for a complete list. The Gnu version of grep added a number of new options and alternative ways to use the options, shown in Table 3.6. The Gnu grep options work with all the different variants of grep, including grep -G, -E, and -F, as shown in Table 3.7.
|Option||What It Does|
|-b||Precedes each line by the block number on which it was found. This is sometimes useful in locating disk block numbers by context.|
|-c||Displays a count of matching lines rather than displaying the lines that match.|
|-h||Does not display filenames.|
|-i||Ignores the ...|