How to search for text files only ?

[cogset]

I've found out this is not as easy as I thought at first,on the other OS we know,all text files usually end with the .txt extension,which makes searching for them quite straightforward-no such thing on Linux,so how can I search for text files in a directory where they may be (and actually are) intermixed with all kinds of other files ? Typically (despite using Tomboy as well) I take lots of unorganized notes as short text files,which then end up somewhere in my home directory,then at some point I'd want to grep for a search term or string among all these files,but there's all sorts of other files in between,so a simple command the likes of find ~ -type f |grep [string] won't cut it,obviously

[Adam_GUI]

Catfish is a great GUI tool for searching local files.
It's in the repos. Search Synaptic or Software Center or "sudo apt-get install catfish".

Set search folder to /home/<Your_User_Name_Here>
Search for *.foo
All file types "Foo" will show up in Catfish's search results.

It also has a filter for file types. If you want just text files for a string, say, "Resume." All related text type files will appear in the field.

Also, create a directory for notes! /home/USER/Documents/NOTES would solve a lot of your headache and help narrow what you're searching for.
You can change Tomboy's default save directory under Preferences > Synchronization.

Unless you're asking for a way to search a text string within the body of a set of text files. It's unclear what you're really asking for.

[slickymaster]

find . -exec sh -c "file -b --mime-type {} | grep -q '^text/'" \; -print

[prodigy_]

on the other OS we know,all text files end with the .txt extension

Unfortunately that's not true. Extension is a convenience tool, it doesn't magically define file type. It can be deliberately misleading or even completely absent.

[cogset]

Thanks folks for all the insights,not least the simple advice of creating a dedicated directory just for notes:I'm now giving Catfish a try,although the string suggested above

find . -exec sh -c "file -b --mime-type {} | grep -q '^text/'" \; -print

is probably what I was after,if only I could understand what it actually does in detail .
I also probably didn't explain myself very well,so I'll try to do better this time-the typical scenario would be like that:I have an habit of taking lots of short notes as text files scattered around my home directory (/home itself,Documents,Desktop and some subdirectories-I know,that's not very tidy,paradoxically I do this in the effort of avoiding to clutter Tomboy with possibly unworthy stuff),then at some point remember that one of those notes was about,say,"firefox bookmarks",now I'd like to grep for this exact string amongst *all* text files in my entire home directory,and that's the hard part,as there's no extension identifying them as text files.

[Vaphell]

find . -exec sh -c "file -b --mime-type {} | grep -q '^text/'" \; -print

=

find <current_dir> (get mime of the file and check if 'text/' is in it) -print file

bold part is responsible for checking mimetype
-exec is used to embed external commands in find, sh -c opens a subshell where file -b --mimetype {} is executed ({} is a placeholder for the currently processed filename)

$ file -b --mime-type sample.txt
text/plain
$ file -b --mime-type test.c
text/x-c

that output is passed to grep to figure out if the phrase text/ appears in it at the very beginning. Grep ends with exit code of 0 (success) or 1 (failure). -print part that prints out the current {} depends on that exit code: success = execute, failure = skip. In short the whole -exec sh -c acts here as a condition controlling the -print part

[dragonfly41]

now I'd like to grep for this exact string amongst *all* text files in my entire home directory,and that's the hard part

If it is string matching you want throughout *all* text files then I would recommend trying Recoll package which is found in Ubuntu Software Centre.

First it has to index all your files.

[elliotn]

I just do

locate *.txt

[dragonfly41]

that doesn't find strings within *.txt

[slickymaster]

find . -exec sh -c "file -b --mime-type {} | grep -q '^text/'" \; -print

=

find <current_dir> (get mime of the file and check if 'text/' is in it) -print file

bold part is responsible for checking mimetype
-exec is used to embed external commands in find, sh -c opens a subshell where file -b --mimetype {} is executed ({} is a placeholder for the currently processed filename)

$ file -b --mime-type sample.txt
text/plain
$ file -b --mime-type test.c
text/x-c

that output is passed to grep to figure out if the phrase text/ appears in it at the very beginning. Grep ends with exit code of 0 (success) or 1 (failure). -print part that prints out the current {} depends on that exit code: success = execute, failure = skip. In short the whole -exec sh -c acts here as a condition controlling the -print part

Congratulations on a clear, succinct and perfect explanation.