Count occurence of character in files - linux

Question

I want to count all $ characters in each file in a directory with several subdirectories.
My goal is to count all variables in a PHP project. The files have the suffix .php.
I tried
grep -r '$' . | wc -c
grep -r '$' . | wc -l
and a lot of other stuff but all returned a number that can not match. In my example file are only four $.
So I hope someone can help me.
EDIT
My example file
<?php
class MyClass extends Controller {
$a;$a;
$a;$a;
$a;
$a;

Answer 1

To recursively count the number of $ characters in a set of files in a directory you could do:
fgrep -Rho '$' some_dir | wc -l
To include only files of extension .php in the recursion you could instead use:
fgrep -Rho --include='*.php' '$' some_dir | wc -l
The -R is for recursively traversing the files in some_dir and the -o is for matching part of the each line searched. The set of files are restricted to the pattern *.php and file names are not included in the output with -h, which may otherwise have caused false positives.

Answer 2

For counting variables in a PHP project you can use the variable regex defined here.
So, the next will grep all variables for each file:
cd ~/my/php/project
grep -Pro '\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' .
-P - use perlish regex
-r - recursive
-o - each match on separate line
will produce something like:
./elFinderVolumeLocalFileSystem.class.php:$path
./elFinderVolumeLocalFileSystem.class.php:$path
./elFinderVolumeMySQL.class.php:$driverId
./elFinderVolumeMySQL.class.php:$db
./elFinderVolumeMySQL.class.php:$tbf
You want count them, so you can use:
$ grep -Proc '\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' .
and will get the count of variables in each file, like:
./connector.minimal.php:9
./connector.php:9
./elFinder.class.php:437
./elFinderConnector.class.php:46
./elFinderVolumeDriver.class.php:1343
./elFinderVolumeFTP.class.php:577
./elFinderVolumeFTPIIS.class.php:63
./elFinderVolumeLocalFileSystem.class.php:279
./elFinderVolumeMySQL.class.php:335
./mime.types:0
./MySQLStorage.sql:0
When want count by file and by variable, you can use:
$ grep -Pro '\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' . | sort | uniq -c
for getting result like:
17 ./elFinderVolumeLocalFileSystem.class.php:$target
8 ./elFinderVolumeLocalFileSystem.class.php:$targetDir
3 ./elFinderVolumeLocalFileSystem.class.php:$test
97 ./elFinderVolumeLocalFileSystem.class.php:$this
1 ./elFinderVolumeLocalFileSystem.class.php:$write
6 ./elFinderVolumeMySQL.class.php:$arc
3 ./elFinderVolumeMySQL.class.php:$bg
10 ./elFinderVolumeMySQL.class.php:$content
1 ./elFinderVolumeMySQL.class.php:$crop
where you can see, than the variable $write is used only once, so (maybe) it is useless.
You can also count per variable per whole project
$ grep -Proh '\$[a-zA-Z_\x7f-\xff][a-zA-Z0-9_\x7f-\xff]*' . | sort | uniq -c
and will get something like:
13 $tree
1 $treeDeep
3 $trg
3 $trgfp
10 $ts
6 $tstat
35 $type
where you can see, than the $treeDeep is used only once in a whole project, so it is sure useless.
You can achieve many other combinations with different grep, sort and uniq commands..