In bash (Terminal on OS X), I enter:
The database server with name walker is running (verified in SQL Central), see attached screenshot.
asked 23 Aug '16, 09:46
Just because the server is running (and I presume you implied it is running on the same computer), does not mean that the connection string that you gave ( "Server=walker;uid=user;pwd=password;" ) will be enough information to connect to it. For example, this connection string would require that the client can connect to the server through shared memory (aka SHMEM) but if the server had been configured using a different tmp directory (e.g. using SATMP env var) than what the client was configured with then the client would not be able to connect.
I suggest that you check the configuration of the server and client and/or change the connection string to connect via TCPIP (i.e. add LINKS=TCPIP) and then try again.
More on trouble shooting connections can be found in the documentation.