Please help me with sed

gazj · 2009-05-27 20:20:36

I need sed to rearange a csv file, I need to change the a comma into a tab followed by a pipe symbol. Then pass the outputing string through echo. I only get a space instead of a tab, anyone know why?

soutput=`cat $DATFILE  | grep -i $PRS | cut -d ',' -f 1-5 | sed 's/,/\t|/g'`

brisbin33 · 2009-05-27 20:28:01

this worked for me, should get you going... 's///g' means literal, for \t to expand tab you need "s///g" (double quotes).

┌─[ 16:20 ][ blue:~ ]
└─> echo 'one,two,three,four' > temp
┌─[ 16:26 ][ blue:~ ]
└─> sed -i "s/,/\t|/g" temp
┌─[ 16:26 ][ blue:~ ]
└─> cat temp
one     |two    |three  |four

Peasantoid · 2009-05-27 20:33:30

My experience is that \t isn't expanded in double quotes (shell: bash). This should work, though:

soutput=`cat $DATFILE  | grep -i $PRS | cut -d ',' -f 1-5 | sed $'s/,/\t|/g'`

Note the dollar sign in front of the sed substitution string.

edit: That's odd, never mind. It seems that sed expands \t on its own.

Last edited by Peasantoid (2009-05-27 20:35:31)

Procyon · 2009-05-27 20:36:50

I don't think the problem is \t expansion (it should work with ", ', or \\t), but how you check whether the tabs are really there:

--> echo 'a,b,c' | sed 's/,/\t|/g'
a    |b    |c
--> out=$(echo 'a,b,c' | sed 's/,/\t|/g')
--> echo $out
a |b |c
--> echo "$out"
a    |b    |c

Peasantoid · 2009-05-27 20:39:29

Procyon: Good call. To clarify, whitespace (such as spaces, tabs, etc.) separates shell args, and echo separates each argument with spaces.

brisbin33 · 2009-05-27 20:47:55

learn somethin new everyday...

gazj · 2009-05-27 20:51:00

I changed my script with your sed command Peasantoid, Thank you very much

Still was only getting one space, so I also done as you said Procyon and it worked

Going on the idea of c64 basic (am showing the only means of programming I am good at and showing my age)
echo "$out" (or print "$out" in basic)

I would expect to get

$out

I thought the -e switch in echo enabled \t and friends.

Either way it works and I have learn't something new

Thanks Guys

karol · 2009-05-27 21:26:38

gazj wrote:

echo "$out" (or print "$out" in basic)
I would expect to get
$out

First you set 'out' to mean $sth, and than you call it.

Procyon wrote:

--> out=$(echo 'a,b,c' | sed 's/,/\t|/g')
--> echo $out

I don't know c64 basic, but I've heard that QBasic is a great language - Windows was written in QBasic ;-)

gazj · 2009-05-27 22:08:27

yes in c64 basic

print out$

would produce the value of out$

but

print "out$"

would print exactly what is inside the quotes in this case out$, I would have expected similar with bash, but this was not the case

karol · 2009-05-27 22:23:04

Ah, the wonderful world of quoting rules :-)

.:B:. · 2009-05-27 23:14:49

You don't need the cat either btw...

grep -i $PRS $DATFILE

would do what you need

Arch Linux

#1 2009-05-27 20:20:36

Please help me with sed

#2 2009-05-27 20:28:01

Re: Please help me with sed

#3 2009-05-27 20:33:30

Re: Please help me with sed

#4 2009-05-27 20:36:50

Re: Please help me with sed

#5 2009-05-27 20:39:29

Re: Please help me with sed

#6 2009-05-27 20:47:55

Re: Please help me with sed

#7 2009-05-27 20:51:00

Re: Please help me with sed

#8 2009-05-27 21:26:38

Re: Please help me with sed

#9 2009-05-27 22:08:27

Re: Please help me with sed

#10 2009-05-27 22:23:04

Re: Please help me with sed

#11 2009-05-27 23:14:49

Re: Please help me with sed

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