How do I find a file that may not be fully-qualified by using the environment path?
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07-07-2019 - |
Question
I have an executable name, like "cmd.exe" and need to resolve it's fully-qualified path. I know the exe appears in one of the directories listed in the PATH environment variable. Is there a way to resolve the full path without parsing and testing each directory in the PATH variable? basically I don't want to do this:
foreach (string entry in Environment.GetEnvironmentVariable("PATH").Split(';'))
...
There has to be a better way, right?
Solution
This seems like a pretty good way of doing it already -- as far as I know, searching through the directories in the PATH
environment variable is what Windows does anyway when it's trying to resolve a path.
OTHER TIPS
Here's another approach:
string exe = "cmd.exe";
string result = Environment.GetEnvironmentVariable("PATH")
.Split(';')
.Where(s => File.Exists(Path.Combine(s, exe)))
.FirstOrDefault();
Result: C:\WINDOWS\system32
The Path.Combine() call is used to handle paths that don't end with a trailing slash. This will properly concatenate the strings to be used by the File.Exists() method.
You could Linq it with
string path = Environment
.GetEnvironmentVariable("PATH")
.Split(';')
.FirstOrDefault(p => File.Exists(p + filename));
A little more readable maybe?
Dan
Well, I did find the following; however, I think I'll stick to the managed implementation.
static class Win32
{
[DllImport("shlwapi.dll", CharSet = CharSet.Auto, SetLastError = false)]
static extern bool PathFindOnPath([MarshalAs(UnmanagedType.LPTStr)] StringBuilder pszFile, IntPtr unused);
public static bool FindInPath(String pszFile, out String fullPath)
{
const int MAX_PATH = 260;
StringBuilder sb = new StringBuilder(pszFile, MAX_PATH);
bool found = PathFindOnPath(sb, IntPtr.Zero);
fullPath = found ? sb.ToString() : null;
return found;
}
}