Problem with sed

tinman47 · September 25, 2011, 5:14pm

ahamed101, I don't know why your codes not working. Seems legit though.

ahamed101 · September 25, 2011, 5:15pm

if solaris, use nawk.
And btw, what does $new_char in your code contain?

root@bt:/tmp# awk -v row=3 -v col=5 -v val='\\E[0;45m' '{if(NR==row){$col=val}}1' input_file
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;45m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m
\E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m \E[0;40m

--ahamed

tinman47 · September 25, 2011, 5:17pm

Oh that was just supposed to contain an escape code.

ahamed101 · September 25, 2011, 5:18pm

Sorry, I didn't get you. Can you show me?

--ahamed

tinman47 · September 25, 2011, 5:21pm

For some strange reason, your code isn't working... Maybe is it because I'm on Cygwin? I can't see any output in my file when I open it.

ahamed101 · September 25, 2011, 5:22pm

new_char='\\E[0;45m' ?

--ahamed

---------- Post updated at 02:22 PM ---------- Previous update was at 02:21 PM ----------

you didn't miss the digit "1" towards the end of the code, did you?

--ahamed

Scrutinizer · September 25, 2011, 5:22pm

ahamed101:

${col} doesn't mean that it will replace in the column you have specified. For eg:-
sed '3 s/you/me/4' file
The above code means, replace "you" with "me" in line #3 for the fourth occurrence of "you" and not in fourth column.

--ahamed

Which would mean the fourth column if all columns are only one character wide.

tinman47 · September 25, 2011, 5:25pm

The digit 1 is there. Where would I place the newchar?

Scrutinizer, the problem with sed, is that when I have to move it to a column, there is more than one occurence of the designated string, so what should I do?

ahamed101 · September 25, 2011, 5:34pm

You are right!

Here in this case, sed doesn't seem to consider \E[0;40m as one char I guess.

--ahamed

---------- Post updated at 02:34 PM ---------- Previous update was at 02:26 PM ----------

Try this... looks odd though!

sed "3 s/\(..\)40m /\145m /5"  input_file > new_file

--ahamed

tinman47 · September 25, 2011, 5:36pm

Nothing! :wall:

That should have worked. Maybe I'm putting in the wrong input file or something. Give me an example on how I should output to a file on the sed statement.

ahamed101 · September 25, 2011, 5:40pm

Try this without redirecting and see if it comes on the screen

sed "3 s/\(..\)40m /\145m /5"  input_file

Please provide the output of the following commands

file input_file

cat -E input_file

od -bc input_file

Hope you didn't edit the file in windows!

--ahamed

tinman47 · September 25, 2011, 5:42pm

IT WORKED! I'm so sorry. I forgot sed doesn't know how to read empty files and I left it empty.

lol This is the best forum ever. Thanks guys.

ahamed101 · September 25, 2011, 5:44pm

oh man!!!...

--ahamed

tinman47 · September 25, 2011, 5:46pm

Now next question! ;D

How would I put a variable in place of the row and column to designate any row or column?

ahamed101 · September 25, 2011, 5:49pm

row=3;col=5;
sed "$row s/\(..\)40m /\145m /$col"  input_file

--ahamed

tinman47 · September 25, 2011, 5:51pm

Incredible! Once again. Thank you.