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I am new to Linux and going through some tutorials and samples. I created a file called test and put alex and alexander in it. I'm trying to find instances of just alex.

If I do grep alex * I get the error:

grep: find: Is a directory.

If I do cat test | grep alex then I get (as expected)

alex alexander (with alex in red)

Why does the first cause an error, and the second produce expected results?

jww

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asked Jul 12 '17 at 1:31

AdoytAdoyt

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Answer 1

If you want to grep phrase from specific file use:

# grep "alex" test

In case you use grep alex * it will search through all files inside the current work directory. In case subdirectory will be met it will tell you something like grep: find: Is a directory
If you want to perform a recursive search use -r key. For example

# grep -r "alex" /some/folder/

In this case all files and files inside subdirectories from /some/folder/ will be checked.
And you can always use man grep.

answered Jul 12 '17 at 1:39

Elvis PleskyElvis Plesky

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Answer 2

Correct answer would be: grep -d skip alex /etc/*

answered Sep 27 '17 at 8:43

Answer 3

Setting the environmental variable GREP_OPTIONS to include the value "--directories=skip" should suppress that "Is a directory" message (i.e. enter GREP_OPTIONS="--directories=skip" or add that line to one of your login initialization files like .bashrc to make that behavior permanent).

> cat test alex alexander  > grep alex *     grep: mysql_data: Is a directory grep: sql_updates: Is a directory test:alex test:alexander grep: tmp_files: Is a directory  > GREP_OPTIONS="--directories=skip"  > grep alex *                       test:alex test:alexander

Also since there is a command named "test" and another named "find" it's usually not advisable to use those as file or directory names. That shouldn't be a problem here but it can lead to other conflicts.

answered Jul 28 '17 at 23:34

Answer 4

Or using grep with -l flag or -w flag

$ grep -l alex /etc/*

To return list of files containing word "alex" in the /etc directory

$ grep -w alex /etc/*

To return list of lines from files in the /etc directory containing "alex" word

answered Jul 25 '17 at 18:27

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Monday, November 18, 2019

Error: grep: find: Is a directory

Error: grep: find: Is a directory

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