Signature
bool path_is_within(String path, String root)
Parameters
path : path to test
root : directory that should contain it
return value : true if
path is inside rootReports whether path lies inside root. It resolves both paths to their canonical form (like path_real()), so they must exist and .. traversal is collapsed first. Use it to reject path-traversal attempts before opening user-supplied paths.
Example
mkdir("/tmp/doc-within");
file_put_contents("/tmp/doc-within/app.txt", "x");
print(path_is_within("/tmp/doc-within/app.txt", "/tmp/doc-within") ? "inside" : "outside", " / ");
print(path_is_within("/tmp/doc-within/../doc-within/app.txt", "/tmp/doc-within") ? "inside" : "outside", "\n");
dir_remove("/tmp/doc-within", true);
Output
inside / inside