The CVTFRMHEX command allows you to convert a variable containing hex
data to a byte variable. A return location and the first invalid
value may be optionally returned.
CL supports the ability to convert a constant (e.g. X'F1') to a
variable, but does not support the conversion from a variable.
A typical command would be:
CVTFRMHEX HEX(&HEX) RTNVAL(&RTNVAL) LEN(10)
This would specify that the first 10 characters of the &HEX variable
should be converted to the first 5 bytes in &RTNVAL. If the value in
&HEX was 'F1C1F2C2F3', the value in &RTNVAL would be '1A2B3'.
The value to be converted must contain valid hex values (0-9, A-F).
The LEN value must be a positive even number. If you are dealing
with variable length data, you must ensure that the LEN value is set
correctly as trailing blanks will be considered invalid.
The RPG program which performs the conversion can be called directly.
See the TAACLPRC source in QATTCL for instructions and the return
code settings.
CVTFRMHEX executes slowly (array processing and bit testing). It
should not be used if a large number of characters needs to be
converted.
If an invalid hex value (such as X'M3')exists, CPF9898 is sent as an
escape message unless the ERRLOC parameter is specified. If ERRLOC
is specified, it will contain 0 if valid hex values exist and if not,
it will contain the location of the first position of the invalid hex
value.
To convert to hex, see the CVTHEX tool.
Command parameters *CMD
------------------
HEX A variable or constant up to 256 bytes in length to
be converted. The data should be left justified.
Only the bytes defined by the LEN parameter will be
converted. If trailing blanks exist, they will be
considered an error if the LEN value specifies that
they be converted.
RTNVAL The return variable. It must be declared as *CHAR
LEN(128) and the converted value will be left
adjusted.
LEN The length of the value to be converted. The
default is 2 meaning that the first two characters
of the HEX parameter will be converted. It must be
a positive even number.
For example, to convert X'F1F2F3F4' you would
specify LEN(8).
ERRLOC The error location if an invalid value such as X'M3'
exists. This is an optional return variable that if
used must be specified as *DEC LEN(3 0).
If a variable is not specified and an invalid hex
value exists, CPF9898 is sent as an escape message.
If a variable is specified, 0 will be returned if
all valid hex values exist. If an invalid hex value
exists, the first position of the invalid value is
returned and the command completes normally.
ERRVALUE The error hex value if it exists. This is an
optional return variable that if used must be be
specified as *CHAR LEN(2).
If ERRLOC is 0, ERRVALUE will contain blanks.
If ERRLOC is not 0, ERRVALUE will contain the
invalid hex value.
Restrictions
-------------
Because the command returns a return variable, it can only be
executed in a CL program.
Prerequisites
-------------
The following TAA Tools must be on your system:
SNDESCMSG Send escape message
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ---- --------- ---------- ----------
CVTFRMHEX *CMD TAACLPR QATTCMD
TAACLPRC *PGM CLP TAACLPRC QATTCL
TAACLPRR *PGM RPG TAACLPRR QATTRPG
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