Script to check folder and create if doesn't exist

[StefanK]

@kafelatte

@StefanK

@kafelatte

… I don’t need to report the folder exists,

There is no dialog in the code.

I mean the error dialog (OS?) that pops up stating folder already exists.

In this case you should check if the shared volume is already mounted to skip the mount line on success.

[JMichaelTX]

So, to recap:

The most clear syntax (IMO) for creating a new directory (folder) IF it does not already exist is:
EDIT: 2016-04-04 14:01 CT

### This revised script corrects errors in DJ's syntax, and provides complete script, which I have tested ###

set newFolderPath to quoted form of (expandPath("~/Documents/Test/NewFolder"))

set cmdStr to "if [[ ! -d " & newFolderPath & " ]]; then 
mkdir -m 755 " & newFolderPath & "; fi"
do shell script cmdStr

on expandPath(pPathStr)
	local fullPath
	set fullPath to pPathStr
	
	if fullPath = "~" then
		set fullPath to (POSIX path of (path to home folder))
	else if fullPath starts with "~/" then
		set fullPath to (POSIX path of (path to home folder)) & text 3 thru -1 of fullPath
	end if
	
	return fullPath
end expandPath

where
newFolderPath is the quoted form of the full POSIX path to the folder.
! is logical NOT
-d is a bash conditional expression that returns TRUE if the folder exists
-m 755 is the mkdir switch to set permissions on the folder to
read, write and execute by the owner, read and execute by group members, read and execute by others, and no set-uid or set-gid behaviour

OR you can use this syntax which makes use of the formulation:
(A OR B)
execute B only if A is false

do shell script "[[ -d " & folderPath & " ]] || mkdir -m 755 " & folderPath

@DJ:

@DJ Bazzie Wazzie

if you want to write it down as compressed as possible it would look like:
[format]if [[ ! -d theFolder]];then
mkdir.;fi[/format]

This code contains numerous syntax errors, which I corrected in my above script.

I would avoid using the -p switch on mkdir because it will change the permissions on an existing directory (folder).

My sincere thanks to all of the great AppleScript gurus above who helped me learn this.
I hope others will find it useful as well.

[Nigel_Garvey]

@JMichaelTX

I appreciate your help, but in the future if there are potentially adverse side effects to a suggestion you are making please tell us about it up front. This especially applies to lesser known scripts like shell scripts. Had I not pursued many follow-up questions about mkdir, I, and probably many other readers, would have not realized this issue.

Look out, JMichaelTX. There are potentially adverse side effects to everything about computer scripting and programming, whether suggested by me or anyone else. It’s up to you to evaluate and test any information you receive to make sure it’s suitable for your purposes. No-one here is expected to second-guess or take responsibility for their advice being used for any purpose other than the one for which it’s intended.

In this thread, the OP wrote:

@dcirona

I need to create an applescript which:

1. maps a network share
2. Checks to see if a folder with the username exists
3. Create it if it doesn’t or do nothing if already there
4. Sets permission on that folder

And later:

. I don’t need to report the folder exists, just if it doesn’t, create, if it does, exit script.

The clear implication is that if the folder exists, it’s because it’s already been created for the same purpose and already has its permissions set for that purpose. My -p suggestion is 100% in accordance with that.

I can’t see anything in your posts above which suggests you might not want the permissions set if the folder already exists. You only ask for an explanation of the logic in the bash script.

I did point out as an afterthought, when it occurred to me, that the -m option is still operative even when the folder already exists ” it’s an easy thing to check for yourself ” but it was more for the benefit of later readers that from any inkling that your requirements were different from the OP’s.

[JMichaelTX]

@Nigel Garvey

Look out, JMichaelTX. There are potentially adverse side effects to everything about computer scripting and programming, whether suggested by me or anyone else. It’s up to you to evaluate and test any information you receive to make sure it’s suitable for your purposes. No-one here is expected to second-guess or take responsibility for their advice being used for any purpose other than the one for which it’s intended.

That’s a nice CYA statement.
Given your reputation, sir, I expected more from you. Consider lesson learned.

I agree that each person has to take full responsibility for using any suggestions or code received from a post on an Internet forum, and to fully understand and test before using.

Having said that, my personal ethics are that if I know of a side effect or adverse result of using something that I am suggesting, then I feel compelled to advise the reader of that. If you choose to throw out suggestions for unsuspecting users without providing any warnings that your already know about, then that is up to you sir.

I surely don’t have to tell you that these threads are for the benefit of all users, not just the one who made the original post. I’m sure you know that other users in search of answers will come along later, and use what they find.

In the case of mkdir is hard to know even where to find documentation if you are not an experienced shell scripter.

Given that the discussion at the time was about testing for an existing folder, you suggested a method that does not just test for the folder, but also sets permissions if the folder does exist. So at the best, IMO, that was bad advice. I still feel that you should have advised us at the time of the suggestion that it also sets permissions.

[DJ_Bazzie_Wazzie]

@JMichaelTX

@DJ:

@DJ Bazzie Wazzie

if you want to write it down as compressed as possible it would look like:
[format]if [[ ! -d theFolder]];then
mkdir.;fi[/format]

This code contains numerous syntax errors, which I corrected in my above script.

Which I did on purpose I though the ‘.’ character speaks for itself.

update: comment on expanding path. Since bash is quite new for you by default the tilde is replaced by the home directory but it can contain a path to any folder. That’s because the tilde is an environment variable.

[JMichaelTX]

@DJ Bazzie Wazzie

@JMichaelTX

@DJ:

@DJ Bazzie Wazzie

if you want to write it down as compressed as possible it would look like:
[format]if [[ ! -d theFolder]];then
mkdir.;fi[/format]

This code contains numerous syntax errors, which I corrected in my above script.

Which I did on purpose I though the ‘.’ character speaks for itself.

LOL, that’s not what I was referring to.

You need a space after the “;” and before the “]]”

Try testing it as you have it, with the “…” replaced, of course.

[DJ_Bazzie_Wazzie]

You don’t need a space behind a ‘;’, it’s an habit I do for better readability when I write shell scripts. The space behind theFolder is the only mistake I have corrected, I have not tested the code and wrote it quickly, my apologies.

[JMichaelTX]

@DJ Bazzie Wazzie

You don’t need a space behind a ‘;’, it’s an habit I do for better readability when I write shell scripts. The space behind theFolder is the only mistake I have corrected, I have not tested the code and wrote it quickly, my apologies.

I am obviously a rank amateur when it comes to shell scripting.
When I tried your example in Terminal, it failed.

I saw two examples using the bash “if” structure, and both of them had a space after the “;”, including yours:

@DJ Bazzie Wazzie

in a more compressed way:

set fileExists to (do shell script "if [[ -e " & quoted form of theFile & " ]]; then
echo yes; else
echo no; fi") as boolean

I also read that in Terminal/Bash, the syntax is very sensitive to spaces.
All I know is that when I added the indicated spaces, the script worked.

[DJ_Bazzie_Wazzie]

@JMichaelTX

I also read that in Terminal/Bash, the syntax is very sensitive to spaces.
All I know is that when I added the indicated spaces, the script worked.

Sometimes it’s better safe than sorry and, yes, bash is sensitive to spaces. Every operator and primary should be surrounded by spaces. To fit all different notations here to make it clear what and what you cannot do in bash.

set fileExists to (do shell script "if [[ -e " & quoted form of theFile & " ]];then echo yes;else echo no;fi") as boolean

But it makes readability worse and probably no Bash scripter, beginner or amateur, would choose that over AND and/or OR operators and definitely experienced ones not. When someone asks a one liner if statement the logical operators are used in Bash. Keep in mind that I do prefer the Bash scripts in do shell script written in a more Bash style than considering AppleScript style, so that only speaks for myself.

[JMichaelTX]

@DJ Bazzie Wazzie

set fileExists to (do shell script "if [[ -e " & quoted form of theFile & " ]];then echo yes;else echo no;fi") as boolean

But it makes readability worse and probably no bash scripter, beginner or amateur, would choose that over AND and/or OR operators. When someone asks a one liner if statement the logical operators are used in Bash.

DJ, maybe you’ve been programming in Bash so long that the (A OR B) technique seems more natural to you, and that’s fine. But I don’t think you can assume that “no bash scripter, beginner or amateur, would choose that over AND and/or OR operators”, because I’m at least one who would.

When I’m reading a language I am not very familar with, use of the “IF/THEN” construct is very clear, and sends an immediate signal to me that this statement is an IF test.

When I see (A OR B), especially when it is used with other strange (to me) syntax like:
do shell script "[[ -d " & folderPath & " ]] || mkdir -m 755 " & folderPath

then I have to stop, and figure out what is really going on here. Add to that, that there are many different symbols for logical OR.

So, IMO, use of IF/THEN is must easier to read than (A OR B).

But we each have our own preferences, and experiences.

[DJ_Bazzie_Wazzie]

@JMichaelTX

But we each have our own preferences, and experiences.

Sure, and it’s also a preference of mine because one is not better than the other. To be clear, I’m not trying to convince you to use otherwise, just showing all the different forms on how to write an if-statement down in Bash. It’s yours to pick the notation you like most.