QGREP (2003 Resource Kit)

Search file(s) for lines that match a given pattern.

Syntax
      QGREP [options] [-e string] [-f file] [-i file] [strings] [files]

Key:
      -L     Search strings literally.
      -X     Treat search strings as regular expressions.
      -B     Match pattern at beginning of line. 
      -E     Match pattern at end of line. 
      -y     Treat upper and lower-case as equivalent.

      -x     Print lines that match exactly.
      -l     Print only the file name if the file contains a match.
      -n     Print line numbers before each matching line.
      -O     Print seek offset before each matching line.
      -v     Print only lines that do not contain a match.
      -z     Print matching lines in MSC error message format. 

   -e string Treat the next argument as a literal search string. 
   -f file   Read search strings from file. 
   -i file   Read file list from file. 
   strings   Specifies the search string(s).
   files     The file(s) to search, which can include wildcard characters
             (* and ?)

Examples:

Find either arg1 or arg2 in FileName.txt:

qgrep "arg1 arg2" FileName.txt

Find arg1 arg2 in FileName:

qgrep -e "arg1 arg2" FileName.txt

White space separates search strings unless the argument is prefixed with -e.
So to find either "all" or "out" in x.y, use:

QGREP "all out" x.y

While to find "all out" use:

QGREP -e "all out" x.y

grep is simply an odd concatenation of the phrase "grab regular expression"

Related:

FINDSTR - Search for strings in files.
Powershell: Where-Object - Filter objects passed along the pipeline.
Equivalent bash command (Linux): grep - Search file(s) for lines that match a given pattern.