Suppose I have search the string which give like the following result
anything1.knownKeyWord anything2.knownKeyWord anything3[1].knownKeyWord How I can write generic syntax for grep such it match all 3 string. I have done like this
^.*\w+\d[\[]?[0]?[\]]?\.knownKeyWord.*$ But I think for indexing eg [1] is not written in good way, how can I achieve so that even i replace [1] with [2342jdsjf], I don't have to change the syntax much.
Using an extended regular expression:
$ grep -E '[[:alnum:]_]+[[:digit:]]+(\[[^]]+\])?\.knownKeyWord' <file anything1.knownKeyWord anything2.knownKeyWord anything3[1].knownKeyWord This would extract any line containing a string on the format
XXXNNN[YYY].knownKeyWord or
XXXNNN.knownKeyWord where XXX is any non-empty alphanumeric string (that may also include _), NNN is any string of (one or more) digits, and YYY is anything not including a ].
Use grep with -x if matches are to be complete lines. Use -w if matches are supposed to be complete words (i.e. not as a substring of something else).
Just using sed to show what each part of the regular expression is matching:
$ sed -E 's/([[:alnum:]_]+)([[:digit:]]+)(\[[^]]+\])?(\.knownKeyWord)/<\1><\2><\3><\4>/' <file <anything><1><><.knownKeyWord> <anything><2><><.knownKeyWord> <anything><3><[1]><.knownKeyWord> Try this,
grep -w 'knownKeyWord$' file.txt From man
-w, --word-regexp
Select only those lines containing matches that form whole words. The test is that the matching substring must either be at the beginning of the line, or preceded by a non-word constituent character. Similarly, it must be either at the end of the line or followed by a non-word constituent character. Word- constituent characters are letters, digits, and the underscore.
