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Your grep invocation will first search for files which contain foo and print a list of the lines from each which contain the word foo; the second grep invocation will take this list and filter it d...
Answer
#1: Initial revision
by
Canina
·
2023-06-09T11:11:57Z (11 months ago)
Your `grep` invocation will first search for files which contain `foo` and print a list of the lines from each which contain the word `foo`; the second `grep` invocation will take this list and filter it down to only those lines of output which also contain `bar`.
A complicating factor is that **XML syntax is relatively complex and does not really lend itself well to line-based utilities** such as `grep`. But ignoring that caveat...
If you want to know which files contain *both* `foo` and `bar` on the same line, you can use a regular expression which will match the two in either order. This is similar to my question [How can I write an egrep (grep -E) regexp that matches lines containing two stanzas in arbitrary order?](https://software.codidact.com/posts/279593), but for something like your use case, one can use for example
grep -rn '\b(foo|bar)\b.*\b(foo|bar)\b' .
This isn't perfect, since it will match a line containing, say, `foo foo`. (It's probably possible to use negative lookbehind to find only those where the *other* word occurs later.)
A more robust solution for finding those files which actually contain both is to search for one, then search each of those files for the other. For this, grep's `-l`/`--files-with-matches` comes in handy.
grep -rlw foo .
will print a list of all files under the current directory which contain the word-separated string `foo`. Adding `-Z` will also cause `grep` to print the file names separated by NULL characters instead of newlines, which helps to protect against special characters. Then use `xargs` (and its corresponding `-0` option to expect input entries to be separated by NULLs rather than newlines) to pass that list of files to a second `grep` invocation which looks for `bar` in each of those files:
## Proposed possible solution
grep -rlwZ foo . | xargs -0 grep -w bar
This should produce a list of all files, and only those files, under the current directory, which contain *both* `foo` and `bar` as whole words, but without regard to their relative location within the file.