egrep

Search file(s) for lines that match an extended expression (extended grep)

Syntax

      egrep [ options ] 'PATTERN' files ...

egrep is the same as `grep -E’

all other options are the same as grep
The PATTERN is a regexp. In typical usage, the regexp is quoted to prevent the shell from expanding any of the special characters as file name wildcards. Normally, `egrep’ prints the lines that matched.
If multiple file names are provided on the command line, each output line is preceded by the name of the file and a colon.
Options

  -c
     Print out a count of the lines that matched the pattern, instead
     of the lines themselves.

  -s
     Be silent. No output is produced, and the exit value indicates
     whether or not the pattern was matched.

  -v
     Invert the sense of the test. `egrep' prints the lines that do
     *not* match the pattern, and exits successfully if the pattern was
     not matched.

  -i
     Ignore case distinctions in both the pattern and the input data.

  -l
     Only print the names of the files that matched, not the lines that
     matched.

  -e PATTERN
     Use PATTERN as the regexp to match.  The purpose of the `-e'
     option is to allow patterns that start with a `-'.