shell script: Add details in a file

[summersnowy]

I'm writing a shell script to add some details into a file. I'm not sure how to save the details into a file. I've written the script that can accept the details but how do I save them into my file?

---------------------
#!/bin/sh
echo "Item: \c"
read a
echo "Quantity: \c"
read b

`??? >>itemFile`
#How do I append the details into my file?

----------------------
My itemFile:

Item Quantity
Printer 10
Monitor 120
Keyboard 120

How can I add the item and quantity details into my itemFile?

[James R. Ferguson]

Hi:

...
read a
echo $a >> itemfile
echo "Quantity: \c"
read b
echo $b >> itemfile

Regards!

...JRF...

[Ian Dennison_1]

Use cat and awk

cat itemfile |awk -v printer=$a '$1 ~ /Printer/ {print $1" "printer}' >/tmp/itemnew
mv /tmp/itemnew itemfile

This only works if there is only 1 entry called "Printer" per file.

If you want to treat flat files as a potential 'database', then store the data in the best possible format, and then reformat it when you want to display it,.... so this example if best stored on 1 line per record (a record being a group of related variables with a unique key - basic DB management principles)

eg. [User] [Printer] [Monitor] [Keyboard]
The above line format, delimited by spaces, would look like this,...

Bob 10 120 120

You would retrieve field 2 to get the Printer Count, and use a similar awk statement to the one above, but keyed on User.

Share and Enjoy! Ian

[john korterman]

Hi,
if you only want to append, try this:
#!/bin/sh
ITEMFILE=/tmp/items
echo "Item: \c"
read a
echo "Quantity: \c"
read b
echo $a $b >>$ITEMFILE

regards,
John K.

[John Meissner]

#!/bin/sh
echo "Item: \c"
read a
echo "Quantity: \c"
read b
echo $a >> file1
echo $b >> file2
paste file1 file2 >> file3


This will put the entries next to each other to easier reading

[summersnowy]

What if I don't want to use append, what else I can do to add my details into a file?

[john korterman]

Hi,
I guess you would like to test whether an item is already present in the itemfile or not. A small test for that could be made like this:

#!/bin/sh
ITEMFILE=/tmp/items
[ -r $ITEMFILE ] || touch $ITEMFILE
echo "Item: \c"
read a
echo "Quantity: \c"
read b

# Is item already present?
grep "^$a" $ITEMFILE
if [ "$?" = "0" ]
then
# yes, "overwrite"
OTHER_ITEMS=`grep -v "^$a" $ITEMFILE`
echo "$OTHER_ITEMS\n$a $b" >$ITEMFILE
else
# no, append
echo $a $b >>$ITEMFILE
fi

However, the original order of items is not kept.

regards,
John K

[Reinhard Burger]

If you want to update informations inside the file then would take the solution provided by Ian. This will update the information stored in your file

[John Meissner]

of course if you are adding ammounts to existing ammounts you could do it like this

ptr=$(cat itemfile | grep Printer | awk '{print $2}')
mtr=$(cat itemfile | grep Monitor | awk '{print $2}')
kbd=$(cat itemfile | grep Keyboard | awk '{print $2}')

echo "Enter item:\c"
read a
echo "Enter quantity:\c"
read b
if [ $a = "Printer" ]
then
((c=$b+$ptr))
echo sed 's/$ptr/$c/g' itemfile > itemfile2" > itemswap.sh
chmod +x itemswap.sh
./itemswap.sh
mv itemfile2 itemfile
elif [ $a = "Montitor" ]
then
((c=$b+$mtr))
echo "sed 's/$mtr/$c/g' itemfile > itemfile2" > itemswap.sh
chmod +x itemswap.sh
./itemswap.sh
mv itemfile2 itemfile
# do the same for any instances of the item you want to update
fi