Question

I’m trying to use PHP to create a shell script on Windows. It’s part of some larger functionality.

Here’s my script:

$contents_str = ''.
'#!/bin/bash
yes | apt-get update
yes | apt-get upgrade
useradd sudoer -g sudo -s /bin/bash -m
echo "sudoer:sudoerpass" | chpasswd';

However, when this file gets on the server, I get a “bad interpreter – no such file or directory” error. I know it’s because I have some hidden windows characters in the file.

Is there a function or script I can use to remove hidden windows characters in PHP? Alternatively, is there a single bash command I can use to do this on the server?

I’ve used dos2unix on the file and it works after I do this, but I’d rather not use dos2unix because it’s something I’d have to install on the server and I need something I can use right out of the Ubuntu box.

Thanks.

EDIT:

I just found a way to clean up the string using preg_replace.

Here’s the code (of course, continuing from the code I already posted above):

$contents_nixsafe_str = preg_replace('/(\r\n|\r|\n)/s', "\n" , $contents_str);

This worked without any issues for me.

Thanks for all the responses

Answer 1

I assume you are using an editor that outputs line-ending (EOL) characters in Windows’s CRLF format. Depending on the editor, you may be able to tell it to use UNIX line endings (LF) instead.

Alternatively, you can concatenate the lines together and manually append the EOL character:

$contents_str = ''
  .'#!/bin/bash'."\n"
  .'yes | apt-get update'."\n"
  .'yes | apt-get upgrade'."\n"
  .'useradd sudoer -g sudo -s /bin/bash -m'."\n"
  .'echo "sudoer:sudoerpass" | chpasswd';

It’s ugly, but gets the job done.