topic Re: Sending a Unix command and masking the percent % sign in SAS Programming

Sending a Unix command and masking the percent % sign

_Dan_ — Wed, 01 Aug 2018 10:15:27 GMT

Hi,

A brief description of my intent: I'm scanning file systems across several Unix servers. The Unix command is created dynamically in a Macro and used to be submitted via 'call systask'. I want to submit the statements in parallel, so now I'm going to use 'systask command nowait'.

As I'm no long using the data _null_ with call systask I'm now building the Unix command in a fairly straightforward (but admittedly messy) %let statement.

The command works, however, the Unix command contains the percent % symbol and so the macro processor is trying to resolve things that don't exist. I know I can use %nrstr() to resolve this (that's what I did with call systask) but this is not masking anything within the %let / systask command statement.

It's a simple loop macro, but here's the line that builds the Unix command:

%let cmd = ssh -o StrictHostKeyChecking=no %sysfunc(quote(%sysfunc(scan(&server.,&i.,|)))) "find &dir. -type f -exec stat -c %nrstr('%n|%y|%x|%s|%U|%u|%G') {} \%nrstr(;)" > &projDir./Data/&fname.Logs_%sysfunc(scan(&server.,&i.,|)).txt;
systask command %sysfunc(quote(&cmd.)) nowait;

When it's compiled It looks like this:

ssh -o StrictHostKeyChecking=no "servername" "find /dir1/dir2/dir3/ -type f -exec stat -c '%n|%y|%x|%s|%U|%u|%G' {} \;"" > /dir1a/dir2a/dir3a/filename_servername.txt

This code may send shivers down the spine of more seasoned coders - I have got myself in a rut because I've had to try all sorts of different methods to get this to work, so the code is admittedly not as efficient or tidy as I'd like.

Any help regarding the forcible masking of the percent symbols is appreciated.

Dan

Re: Sending a Unix command and masking the percent % sign

Kurt_Bremser — Wed, 01 Aug 2018 10:31:33 GMT

I would unload the whole UNIX code into a shell script that accepts all variable parts from the commandline ($1, $2 and so on). That way SAS never sees the format parameters etc, which are fixed in the script.

Create a control table with all the information (server, diractory, file names), build the commandline in a data _null_ step, and use call execute to call the systask statement.

Re: Sending a Unix command and masking the percent % sign

_Dan_ — Wed, 01 Aug 2018 10:33:09 GMT

Thanks for your reply & that's certainly a good option. I will need to consider it as a "last resort" of sorts until I've exhausted any options on coding it directly into the SAS Macro.

Re: Sending a Unix command and masking the percent % sign

_Dan_ — Wed, 01 Aug 2018 11:04:46 GMT

I've found the resolution: superq.

Here's the end result.

%let cmd = ssh -o StrictHostKeyChecking=no %sysfunc(quote(%sysfunc(scan(&server.,&i.,|)))) "find &dir. -type f -exec stat -c %nrstr('%n|%y|%x|%s|%U|%u|%G') {} \%nrstr(;)" > &projDir./Data/&fname.Logs_%sysfunc(scan(&server.,&i.,|)).txt;
systask command "%superq(cmd)" nowait;