C# - Check if unix folder exists

Question

I need to verify that a unix folder exists, from my C# application using SharpSsh.
I thought of trying this:

SshExec.RunCommand("-d " + folder)

But the result is always '2' regardless if the folder is there or not. I could implement something using:

Sftp.GetFileList(folder)

But prefer not to because this folder may contain numerous files and It causes a delay while all of them are retrieved which is not elegant.

Any ideas?

Edit: I tried this:

string folder = "/foldername";
string result = sshExec.RunCommand("[ -d " + folder + "] && echo 'true' || echo 'false'");

if (result == "false") 
throw new Exception("Directory " + foldername+ " + is not found.");

String 'result' is set as "false\n" even though the directory exists. If I skip the check I can work with the directory without problems.

How about doing a bash script: `if [ -d {folder}]; then echo "yes"; else echo "no"; fi`? — Candide, Dec 03 '12 at 16:30
Is this used like this: SshExec.RunCommand(if [ -d {folder}]; then echo "yes"; else echo "no"; fi?) — Yoav, Dec 06 '12 at 12:39

Carlos Landeras · Answer 1 · 2012-12-03T16:51:01.907

2

Use

SshExec.RunCommand("ls -la " + folder)

or

SshExec.RunCommand("ls " + folder)

if your folder is not hidden and you dont need size information

Cheap command that will fill your output string with permissions and folder info if exists

edited Dec 03 '12 at 16:51

answered Dec 03 '12 at 16:30

Carlos Landeras

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OP says: "folder may contain numerous files". If you had hundreds of thousands of files in that folder... it's not very efficient. – Candide Dec 03 '12 at 16:31
You pass the folder name so it filters it – Carlos Landeras Dec 03 '12 at 16:34
Try it "ls -la foldername" result should be one line or nothing if it doesnt exist – Carlos Landeras Dec 03 '12 at 16:36
The man says: "-a Include directory entries whose names begin with a dot (.)." So, `ls -a` for 100k files with about 20 chars on average per file name will return about 2MB of data. – Candide Dec 03 '12 at 16:38
Its not ls -la. It is ls -la foldername. If you dont put foldername you get all. With name you filter – Carlos Landeras Dec 03 '12 at 16:41
It doesn't matter. `ls -la {folder}` means `ls -l -a {folder}` – Candide Dec 03 '12 at 16:43
-a its to include hidden folder with dot (.) Please just try to run the command giving the foldername at the end. If you look for folder "mypersonalfolder" put ls -l mypersonalfolder. – Carlos Landeras Dec 03 '12 at 16:45
you dont even need the -a (if not hidden) and -s if you dont want size information, just "ls mypersonalfolder" – Carlos Landeras Dec 03 '12 at 16:48
With ls you need the -d option, not -a – loreb Dec 03 '12 at 20:03
This command returns a list of files in the folder. If the folder is empty then it returns an empty string. – Yoav Dec 06 '12 at 13:57

C# - Check if unix folder exists

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