Why Is Grep Returning No Matches?

To match no lines at all, use an extended regular expression like ' a^ ' or ' $a '. To match every line, a portable script should use a pattern like ' ^ ' ...

Can I make `find` return non-0 when no matching files are found?

grep -q will cause find to likely exit with SIGPIPE , which will be a problem if you use -o pipefail . – Vladimir Panteleev. Commented Feb 1, ...

grep not working with CSV files - Ubuntu Forums

But that returned no matches. After some testing, I discovered that grep thinks CSV files are all binary (all the files are *.csv). So, I ...

Ignoring trap command for a grep function

However, when the grep command does not match any lines in the input file, returns zero as its exit code. No, it returns 1 as it's exit code if it doesn't match ...

SOLVED: Using grep to display from the start of match | Linux.org

To be clear, it is not grepping everything from the start of the match. It is only grepping the match inside the quotes. Anything following the ...

Return Value of a Grep - Spiceworks Community

-f tells you the filenames that contained any match. So if there are no matches, grep reads the whole file and prints nothing. That's an answer.

The grep function does not return all the matches - Posit Community

One is that you haven't been clear about the problem you are running into with this code. What text is it that you expect your regex to match?

[SOLVED] grep search returns non existent words

You are not using the regex correctly. The '*' matches any number of the previous character. If the previous character is 'b' it will match any ...

[R] what is returned if a match is not found using grep

... grep man page. By default, R returns a >> vector of indices of entries in x that match the pattern. Since you >> have no matches, you get a ...

String.prototype.match() - JavaScript - MDN Web Docs

returns ["number"] str1.match(NaN); // the type of NaN is the ... in a regex matches any character. In order to make it only match ...

Problem with GREP - AppleScript | Mac OS X - MacScripter

Also, Mark67's point still holds. The period “.” is a metacharacter for normal grep. It is a single character “wildcard” (it will match any character). So as ...

grep command in Unix/Linux - GeeksforGeeks

By default, grep matches the given string/pattern even if it is found as a substring in a file. The -w option to grep makes it match only the ...

grep returns Binary file (standard input) matches - Arch Linux Forums

The grep -a, --text option may be of use to you. This will force grep to actually print the contents of the file ...

Using find utility on file names | binary output

Another possibility would be to add a -o flag to direct grep to return just the match. But this is less than ideal as well. If you were looking ...

git-log Documentation - Git

... match the specified pattern (regular expression). With more than one --grep-reflog , commits whose reflog message matches any of the given patterns are chosen.

Regular expression - Wikipedia

A regular expression sometimes referred to as rational expression, is a sequence of characters that specifies a match pattern in text. Usually such patterns ...

Regular expressions - JavaScript - MDN Web Docs

It returns true or false . match(), Returns an array containing all of the matches, including capturing groups, or null if no match is found.

Regex Generator - Creating regex is easy again!

Most regex will work without -P. grep -P -i '2020-03-12T13:34:56\.123Z INFO ... IGNORE_CASE)) return regex.matches(input) }. PHP.

Unix & Linux: Can grep return true/false or are there ... - YouTube

That outputs (not return as exit code), the number of lines that match the pattern, so 0 if there's no match or 1 or more if there's a match.

Mocha - the fun, simple, flexible JavaScript test framework

When the worker completes the test file, buffered results are returned ... Previous to v3.0.0, .only() used string matching to decide which tests to execute; this ...