Help with `call-process-region`: Searching for program: no such file or directory

Question

I have the following snippet:

(call-process-region (point-min) (point-max) 
   "python /Users/myname/code/move_imports/moveimports.py")

Incredibly, it tells me that it cannot find the file, even though it exists in the very same location given. Same happens with

(call-process-region (point-min) (point-max) 
   "/Users/myname/code/move_imports/moveimports.py"))) ; Using shebang in python file

How can I fix this problem and run the executable by using the full path?

edit: The error I am getting is Searching for program: no such file or directory.

Answer 1

The 3rd argument to call-process-region is an executable file name, not a whole command, so you should call it like this:

(call-process-region
 (point-min) (point-max) "python" nil nil nil
 "/Users/myname/code/move_imports/moveimports.py")

This looks for an exectutable named python that should be located in one of the directories listed in exec-path (you could provide the full path to python instead).

The original call would attempt to execute a file called moveimports.py under a subdirectory named python /Users/myname/code/move_imports/.

---

You may find it easier to use shell-command-on-region which would work with your first form:

(shell-command-on-region
 (point-min) (point-max) 
 "python /Users/myname/code/move_imports/moveimports.py")

You do have to watch out for spaces in file names and other shell meta-characters in this case though. Also note that the shell uses the environment variable PATH which usually (but not necessarily) contains the same list (encoded to a : separated string) as exec-path (especially Mac users should consider using exec-path-from-shell).

---

I believe the second form

(call-process-region (point-min) (point-max) 
   "/Users/myname/code/move_imports/moveimports.py"))) ; Using shebang in python file

should work unless "/Users/myname/code/move_imports/moveimports.py" is not marked executable, or its shebang is incorrect.