Shell Programming and Scripting

there is a file test_jan2 in my present directory and i just need to replace some things and write into different file

the script looks like this


after this the test2 is being formed with 0 bytes. can somebody suggest?

Code:

#!/bin/ksh

while read i
do
    sed -e 's/google/rediff/g' -e 's/streams/promos/g' "${i}" > test2
done < test_jan2

still the same problem

+ sed -e s/google/rediff/g -e s/streams/promos/g google
+ 1> test2
Can't open google
+ read i
+ sed -e s/google/rediff/g -e s/streams/promos/g streams
+ 1> test2
Can't open streams
+ read i
+ sed -e s/google/rediff/g -e s/streams/promos/g google
+ 1> test2
Can't open google
+ read i
+ sed -e s/google/rediff/g -e s/streams/promos/g streams
+ 1> test2
Can't open streams
+ read i

ok, 'google' and 'streams' don't exist where 'sed' expects them.

Maybe I don't understand what you're after, but...

Does 'test_jan2' contain a list of files to be edited
OR
Do you want to edit 'test_jan2' files itself?

Hi dsravan,
sed can work the entire file (it may take the test_jan2 as an input). So I don't see the need for it to be fed line by line (for loop). Also if using a loop, you would need to redirect output using the >> to append (> would only overwrite the last line).

Please try this and let us know:

sed -e 's/google/rediff/g' test_jan2 | sed -e 's/streams/promos/g' > test2

If you are using the for loop because you have multiple files, just move the output redirection to the end:

Code:

#!/bin/ksh

for i in test_jan2; do
cat $i | sed 's/google/rediff/g' | sed 's/streams/promos/g'
done > test2

sed is a stream editor, which means it transforms a flow of input into a flow of output by following a flow of instructions. As I can see from your example, you are not providing input to sed; please check the command syntax, as there must be an input source specified or implied. By using the for loop, no standard input is being implied, so at least a filename has to be provided in sed invocation, as: sed 'flow of instructions' input_filename. Also please check the syntax to provide two or more instructions in the same line, because if you don't then you should use "( sed 'command_1' | sed 'command_2' ) <input_filename >output_filename" explicitly.
Hope it helps.