Grep command with multiple patterns

Question

Hi i am currently use this to grep:

$ grep -nri --exclude-dir=DELIVERY_REL "xxxxxx\.h" --colour --include=*.{c,h}

I am trying to fine tune the search results of my grep to include multiple patterns. I have tried multiple ways recommended on stack-overflow on similar questions, but to no avail. What i need to grep:

xxxxxx.h and #include or xxxxxx.h and # include (with a space)

Answer 1

To include multiple pattern to grep command you need option "-e".

For example you can include pattern "pattern1" e "pattern2" in this way:

grep -e "pattern1" -e "pattern2" filename.ext

Answer 2

OR: To search for lines that match regex A or B specify each of the regexes with a preceding -e option in a single grep command: grep -e A -e B. Alternatively, use the alternation operator inside a single regex: grep -E 'A|B'

AND: To print only lines that match regex A and B chain two grep searches: grep A | grep B. Alternatively, list all possible orders in which the regex can match in a single regex: grep -E 'A.*B|B.*A'

For your specific case you could use

grep 'xxxxxx\.h' | grep -E '# ?include'

Here the ? after the space means that the space is optional.
# ?include is equivalent to #include|# include.