Taking advantage of the Shell
The OMVS shell, like other UNIX shells, performs a number of functions
besides simply running commands.
The shell supports metacharacters such as *. For instance,
ls -l a*
will list all files in the current directory beginning with a. The shell
actually replaces the string "a*" in the command with these file names,
so the ls command actually sees "ls -l " followed by a list of files.
If there are no files beginning with a, then the ls command would see
"ls -l a*". The ISEE EXEC can be used to check
out this behaviour. The REXX EXECs on the
OpenEdition and REXX page which work with HFS files have been written
to take advantage of this feature where possible.
Output generated by shell commands can be passed into the command line by
placing them inside backquotes. For example,
ls -l `whence id`
lists the attributes of the id command. The whence command returns the
file location based on the current PATH settings.
Another syntax which is also supported is
ls -l $(whence id)
Environment variables such as $$ (the current process id) or $HOME (the
user's home directory) are replaced in the command line.
Redirection of input and output
Command input or output can be redirected to a file. The output of one
command can be piped to become the input to another command.
See the PIPE EXEC for an example of using this
function from REXX.
Aliases can be used to define new shell commands or redefine existing ones.
The shell maintains a history file of "recently" executed commands.
These commands can be recalled or displayed.
Accessing TSO functions
You can invoke TSO functions from the shell using the tso shell command. If you entered
the shell using the OMVS TSO command, then tso uses this TSO environment by default. For
more consistent behaviour with other environments, you can use the -t option which creates
a mini-TSO environment.
To invoke a REXX member hello stored in a PDS hlq.pds from the shell, you could do the following:
export SYSEXEC="alloc da(HLQ.PDS) shr"
tso -t %hello
To find out more about the tso shell command, you can use the command
For more information
will provide an overview of shell processing. You can also refer to the
"Unix System Services User's Guide" for more information.