Specifying the FTP client API for REXX trace output location: z/OS UNIX environment batch job

When using the z/OS® UNIX environment from a batch job, use one of the following methods to specify the FTP client API for REXX trace output location:

If the application exists in a file system, is invoked using the BPXBATSL utility, and does not perform any fork calls, use the FTPRXTRC DD statement to specify the output location as you would with an MVS™ batch job.
In all other cases, the FTP_REXX_TRACE_FILE environment variable must be set. When using BPXBATSL or BXPBATCH utilities, set this and any other required environment variables using the STDENV DD statement as follows:
```
//STDENV DD JCL statement
```
Following is an example:
```
//STDENV DD DISP=SHR,DSN=USER3.APPL.ENVIRON
```
The STDENV data set can a fixed or variable (nospanned) record format type. It can contain multiple environment variables, as shown in the following sample:
```
FTP_REXX_TRACE_FILE=//'USER3.APPL.RESTRACE'
_BPXK_SETIBMOPT_TRANSPORT=TCPCS
```
Guidelines:
- Environment variables must start in column 1, and the data set must not contain any sequence numbers (sequence numbers would be treated as part of the environment variable).
- For the FTP_REXX_TRACE_FILE environment variable, any blanks from a fixed format STDENV data set are removed. Because this might not be true for all variables, you should use a variable record format data set.
- For applications that fork, you should use an MVS data set. If you use a file system file, a C03 ABEND might occur when the forked process ends.
Restriction: When using the FTP_REXX_TRACE_FILE environment variable, the maximum length for the MVS data set name or the z/OS UNIX file name is 64 characters. If the data set name or file name length exceeds 64 characters, the name is truncated. If the MVS data set is not qualified, the 64 character limit is applied after the high-level qualifier is added. If the z/OS UNIX file path is a relative path, then the 64 character limit is calculated after the current working directory name is added.

See z/OS UNIX System Services Command Reference for additional considerations when using the BPXBATCH or BPXBATSL utilities.