The Scan and Update Data command scans a character field for a string
and changes the string to a new value. Either character data or a
hex value (X'xxxx') may be scanned for. The command is useful for
cleaning up data in a file.
A typical command would be:
SCNUPDDTA SCNVALUE(ABC) NEWVALUE(DEF) FILE(xxx)
SCNFLD(NAME)
Each NAME field would be scanned for the value ABC. Each occurrence
of the ABC value would be replaced by DEF.
You must have *ALL authority to the file to use SCNUPDDTA. The
SNDAUDE TAA Tool is used internally to send an entry to the QAUDJRN
if it exists or QSYSOPR if QAUDJRN does not exist. This provides an
audit trail that SCNUPDDTA was run.
A hex value may also be scanned for and replaced. For example, if
you want to find all the instances of X'00' in the NAME field and
replace it with a blank, you would specify:
SCNUPDDTA SCNVALUE(X'00') NEWVALUE(*BLANK) FILE(xxx)
SCNFLD(NAME)
The SCNFLD parameter defaults to *PROMPT which allows you to prompt
for the field names in the record format.
A spooled file is optional. It will have a line for every record
where the SCNVALUE was found and the position where the string was
found. The data before the change is shown. You may prompt for up
to 3 fields from the record that will assist you in identifying the
records that were changed.
A Translate Table option is available to assist in converting the
data base data before scanning. This is useful if the data is in
lower case.
From 1 to 5 blank characters may be scanned for by using the special
values *BLANK1 - *BLANK5 for SCNVALUE. Blank values may be used for
NEWVALUE if *BLANK is specified.
You may not enter a SCNVALUE or NEWVALUE that is all blank or ends
with a trailing blank. This restriction is due to the fact that the
system does not describe the length of the value passed in and the
value is trimmed of trailing blanks.
The number of characters entered for SCNVALUE and NEWVALUE must be
the same. For example, you cannot scan for ABC and replace it with
DEFG or DE.
Command parameters *CMD
------------------
SCNVALUE The value to be scanned for. Up to 20 bytes may be
entered.
If the data in the data base is in lower case, you
may enter the specific hex value to scan for or
specify the TRNTBL parameter.
A hex value may be specified by entering X'xxxx'.
If you enter a hex value and SPLF(*YES), you should
specify PRTHEX(*YES) to allow the value to be
printed in hex in the spooled file. This will help
identify what type of scan occurred. If PRTHEX(*NO)
is used, the scan value may not be readable.
For example, if you specify X'00' as the scan value,
the spooled file will not identify what you scanned
for unless PRTHEX(*YES) was specified.
An all blank value (X'40') or a trailing blank may
not be scanned for. The scan value is trimmed
before scanning which causes the scan value (such as
X'C1D340') to be trimmed off.
The special values *BLANK1 - *BLANK5 may be used to
scan for one to 5 blanks.
NEWVALUE The new value to replace the string specified for
the SCNVALUE parameter. The new value must be the
same length as the SCNVALUE parameter (you cannot
scan for ABC and replace it with DEFG or DE).
You can insert all blanks by using the special value
*BLANK.
You can enter a hex value such as X'51' or X'5152'.
You cannot enter a value that ends with a trailing
blank or is all blank. For example X'40', X'5140',
and 'DE ' are not valid. If a trailing blank is
used, the system trims off the NEWVALUE data and a
shorter field would result.
FILE The qualified file name of the file to be scanned.
The library value defaults to *LIBL. *CURLIB may
also be used.
A physical or logical file (single format) may be
used.
MBR The member to be scanned. The default is *FIRST for
the first member of the file.
UPDFLD The field to be scanned and updated. It must be a
character field of 500 bytes or less in the named
file. The entire field will be scanned and all
occurrences of the SCNVALUE will be replaced with
the NEWVALUE value.
The default is *PROMPT in which case a subfile is
displayed of all the fields in the file and a
selection may be made.
TRNTBL The Translate Table to be used. The default is
*NONE meaning the SCNVALUE must match the data in
the field to be scanned.
If the data in the field to be scanned is in lower
case, a translate table can be specified to convert
the data before scanning.
*STD may be entered to fold a-z to A-Z. This is the
same function performed by the QSYSTRNTBL table in
QSYS.
A specific translate table and library may also be
entered.
CHGREPORT A *YES/*NO value for whether a spooled file should
be created with the records that were changed. *NO
is the default meaning no spooled file will exist.
*YES may be specified to cause a spooled file to be
created with one line for every value that was
replaced.
If *YES is specified, the IDFLD must not be *NONE.
IDFLD A list of up to 3 fields which will be printed with
each record where the scan value is found if
SPLF(*YES) is specified. If you have a unique key
to the file, the unique key fields should be
specified to help identify the record.
The default is *NONE which may only be used if
SPLF(*NO) is specified.
If SPLF(*YES) is specified, you must name one to
three fields or specify *PROMPT to prompt for the
field.
PRTHEX Whether to print the scan value in hex in the
spooled listing if SPLF(*YES) is specified. The
default is *NO meaning the value will be printed as
character data.
If you enter a hex value for SCNVALUE, you should
specify PRTHEX(*YES) to allow the value to be
printed in hex in the spooled file listing. This
will help identify what type of scan occurred. If
PRTHEX(*NO) is used, the scan value may not be
readable.
Restrictions
------------
See the previous comments.
The record length of the file cannot exceed 9999.
The number of fields cannot exceed 998.
Prerequisites
-------------
The following TAA Tools must be on your system:
CVTHEX Convert hex
EDTVAR Edit variable
EXPVAL Expand value
EXTLST2 Extract list 2
FILEFDBCK File feedback
HLRMVMSG HLL Remove message
PMTFLD Prompt field
RTVFLDARR Retrieve field array
RTVSYSVAL3 Retrieve system value 3
SNDAUDE Send audit entry
SNDCOMPMSG Send completion message
SNDESCMSG Send escape message
SNDSTSMSG Send status message
Implementation
--------------
None, the tool is ready to use.
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ---- --------- ---------- ----------
SCNUPDDTA *CMD TAADBIH QATTCMD
TAADBIHC *PGM CLP TAADBIHC QATTCL
TAADBIHR *PGM RPG TAADBIHR QATTRPG
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