-fc

c (not TAB) is the input column separation character.

-Dn

turn on debugging at level n, or 1 if n is not specified.

-m [bhirs]

See index for the fast access method options.

+a

always append the row to the end of the file, even if it fits in the original row.

-a

if the replacement row is too big to fit in the original position do not append it to the end of the file. This option may be specified in cases where it is critical to maintain a particular row order.

-b

write a blank row at the original position in the file when the record replacing it is larger and must be appended to the end of the file. This eliminates the need to use blank on the original row in a separate process.

$ cat inventory
Item    Amount  Cost    Value   Description
----    ------  ----    -----   --------------
   1         3    50      150   rubber gloves
   2       100     5      500   test tubes
   3         5    80      400   clamps
   4        23    19      437   plates
   5        99    24     2376   cleaning cloth
   6        89   147    13083   bunsen burners

First, extract the row to be updated with the seek program and save the offset in the LOCATION shell variable. This example uses the record method:

$ LOCATION=`echo 5 | seek -mr -o rowupdate inventory Item`
$ echo $LOCATION
207 245 54 62

$ cat rowupdate
Item    Amount  Cost    Value   Description
----    ------  ----    -----   --------------
   5        99    24     2376   cleaning cloth

Now let's change Amount in rowupdate to 44 and update the Value column:

$ compute "Amount = 44;
	 Value = Cost * Amount" < rowupdate
Item    Amount  Cost    Value   Description
----    ------  ----    -----   --------------
   5       44    24     1056   cleaning cloth

Let's repeat that command and replace the old row as well:

$ compute "Amount = 44;
	Value = Cost * Amount" < rowupdate |\\
replace -mr inventory $LOCATION
$ cat inventory
Item    Amount  Cost    Value   Description
----    ------  ----    -----   --------------
   1         3    50      150   rubber gloves
   2       100     5      500   test tubes
   3         5    80      400   clamps
   4        23    19      437   plates
   5        44    24     1056   cleaning cloth
   6        89   147    13083   bunsen burners