#! /usr/bin/python3
# Last edited on 2026-01-12 14:48:38 by stolfi
# python3 functions that check args and print error messages.
# To be imported by other python scripts.

import sys, os, subprocess;

def run_command(command):
  result = subprocess.run(command, text = True, timeout = None)
  if result.returncode != 0:
    print(result.stderr)
    print(result.stdout)
    assert False, f"** {command[0]} failed - returned status = {result}"
  return
  # ......................................................................
  
def bash(cmd):
  # Execute the string {cmd} with "/bin/bash".
  result = subprocess.run([ cmd ], shell = True, executable = "/bin/bash")
  if result.returncode != 0:
    print(result.stderr)
    print(result.stdout)
    assert False, f"** {cmd} failed - returned status = {result}"
  # ......................................................................

def basic_line_loop(rd, process_line):
  # Loops on lines of file {rd}, like the implicit loop of {gawk}.
  # Parses each line using {process_line(nread, line)}.
  # On EOF, returns the count {nread} of lines read. 

  nread = 0
  while True:
    line = rd.readline()
    if line == "":
      # End of file:
      return nread
    nread += 1
    process_line(nread, line)
  assert False # Never reaches here.
  # ----------------------------------------------------------------------