phpgrep

README

phpgrep

Syntax-aware grep for PHP code.

This repository is used for the library and command-line tool development. A good source for additional utilities and ready-to-run recipes is phpgrep-contrib repository.

Overview

phpgrep is both a library and a command-line tool.

Library can be used to perform syntax-aware PHP code matching inside Go programs while binary utility can be used from your favorite text editor or terminal emulator.

It's very close to structural search and replace in PhpStorm, but better suited for standalone usage.

In many ways, inspired by github.com/mvdan/gogrep/.

See also: "phpgrep: syntax aware code search".

Quick start

If you're using VS Code, you might be interested in vscode-phpgrep extension.

Download a phpgrep binary from the latest release, put it somewhere under your $PATH.

Run a -help command to verify that everything is okay.

$ phpgrep -help
Usage: phpgrep [flags...] target pattern [filters...]
Where:
  flags are command-line flags that are listed in -help (see below)
  target is a file or directory name where search is performed
  pattern is a string that describes what is being matched
  filters are optional arguments bound to the pattern

Examples:
  # Find f calls with a single variable argument.
  phpgrep file.php 'f(${"var"})'
  # Like previous example, but searches inside entire
  # directory recursively and variable names are restricted
  # to $id, $uid and $gid.
  # Also uses -v flag that makes phpgrep output more info.
  phpgrep -v ~/code/php 'f(${"x:var"})' 'x=id,uid,gid'
  # Print only matches, without locations.
  phpgrep -format '{{.Match}}' file.php 'pattern'
  # Print only assignments right-hand side.
  phpgrep -format '{{.rhs}}' file.php '$_ = $rhs'

Custom output formatting is possible via the -format flag template.
  {{.Filename}} match containing file name
  {{.Line}}     line number where the match started
  {{.Match}}    an entire match string
  {{.x}}        $x submatch string (can be any submatch name)

Exit status:
  0 if something is matched
  1 if nothing is matched
  2 if error occurred

# ... rest of output

Create a test file hello.php:

<?php
function f(...$xs) {}
f(10);
f(20);
f(30);
f($x);
f();

Run phpgrep over that file:

$ phpgrep hello.php 'f(${"x:int"})' 'x!=20'
hello.php:3: f(10)
hello.php:5: f(30)

We found all f calls with a single argument x that is int literal not equal to 20.

Next thing to learn is ${"*"} matcher.

Suppose you need to match all foo function calls that have null argument.
foo is variadic, so it's unknown where that argument can be located.

This pattern will match null arguments at any position: foo(${"*"}, null, ${"*"}).

Read pattern language docs to learn more about how to write search patterns.

Recipes

This section contains ready-to-use phpgrep patterns.

srcdir is a target source directory (can also be a single filename).

Useful recipes

# Find arrays with at least 1 duplicated key.
$ phpgrep srcdir '[${"*"}, $k => $_, ${"*"}, $k => $_, ${"*"}]'

# Find where `$x ?: $y` can be applied.
$ phpgrep srcdir '$x ? $x : $y' # Use `$x ?: $y` instead

# Find where `$x ?? $y` can be applied.
$ phpgrep srcdir 'isset($x) ? $x : $y'

# Find in_array calls that can be replaced with $x == $y.
$ phpgrep srcdir 'in_array($x, [$y])'

# Find potential operator precedence issues.
$ phpgrep srcdir '$x & $mask == $y' # Should be ($x & $mask) == $y
$ phpgrep srcdir '$x & $mask != $y' # Should be ($x & $mask) != $y

# Find calls where func args are misplaced.
$ phpgrep srcdir 'stripos(${"str"}, $_)'
$ phpgrep srcdir 'explode($_, ${"str"}, ${"*"})'

# Find new calls without parentheses.
$ phpgrep srcdir 'new $t'

# Find all if statements with a body without {}.
$ phpgrep srcdir 'if ($cond) $x' 'x!~^\{'
# Or without regexp.
$ phpgrep srcdir 'if ($code) ${"expr"}'

# Find all error-supress operator usages.
$ phpgrep srcdir '@$_'

# Find all == (non-strict) comparisons with null.
$ phpgrep srcdir '$_ == null'

Miscellaneous recipes

# Find all function calls that have at least one var-argument that has _id suffix.
$ phpgrep srcdir '$f(${"*"}, ${"x:var"}, ${"*"})' 'x~.*_id$'

# Find foo calls where the second argument is integer literal.
$ phpgrep srcdir 'foo($_, ${"int"})'

Install from sources

You'll need Go tools to install phpgrep from sources.

To install phpgrep binary under your $(go env GOPATH)/bin:

go get -v github.com/quasilyte/phpgrep/cmd/phpgrep

If $GOPATH/bin is under your system $PATH, phpgrep command should be available after that.