Open System Services Shell and Utilities Reference Manual (G06.28+, H06.05+)

gtacl(1) OSS Shell and Utilities Reference Manual
The following conditions limit the effectiveness of gtacl filtering:
• Filtering can be used only for data passing through OSS environment standard input, out-
put, and error files and Guardian environment IN, OUT, and STDERR files. Any files
directly opened by a Guardian environment process cannot be filtered.
• Some Guardian processes do not accept a process file as an input or output file. Filtering
will not work with such Guardian processes.
• If filtering is used with redirection and either the -c command or -cv command option, it
cannot be used for filtering standard input. When either of these options is specified,
gtacl ignores its standard input file. For example, the following command will not work
because the input from myfile.tgal is ignored:
gtacl -c ’tgal /OUT $s.#hold/’ <myfile.tgal
Instead, either use an explicit Guardian input file:
gtacl -c ’tgal /IN MYFILE, OUT $S.#HOLD/’
or use the -p pathname option to run TGAL directly:
gtacl -p tgal < myfile.tgal | lp -d hold
• When the -nowait option is used with input/output filtering, the child process can fail to
do either of the following:
— open one or more of the gtacl standard files because gtacl has stopped running
— access one or more of the gtacl standard files because gtacl has stopped running
To avoid these problems, do not use the -c, -cv, -i,or+i options. Use only files that can
be opened from within the Guardian environment for standard input and output when you
use the -nowait option.
Use in Shell Scripts
Guardian processes typically open a Guardian environment disk file for output by requesting pro-
tected or exclusive access. This practice can conflict with use of exclusion mode by an OSS pro-
cess.
For example:
gtacl -p FUP ’INFO *’
fails if it is invoked from an OSS shell script and the output of the script is redirected to a Guar-
dian disk file. Because the output file can be opened from the Guardian environment, gtacl does
not filter the output. However, because the output file is still open by the shell process executing
the script, FUP cannot open the file for exclusive access and terminates abnormally.
To avoid this problem when gtacl is used within a shell script, use the -i or +i option to force
input/output filtering, as follows:
gtacl -i -p FUP ’INFO *’
OSS Environment Variables
The following OSS environment variables affect the execution of the gtacl command.
PMSEARCHLIST
If this variable is defined, gtacl uses the value if necessary to resolve a Guardian
file identifier to find the program specified with the -p or -prog option. The
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