Add quotes and new delimiter around space delimited words

regular expressionsedtext processing

I have the following string

y10_zcis y10_nom y10_infl y20_zcis y20_infl y30_zcis

I would like to transform this to

"y10_zcis", "y10_nom", "y10_infl", "y20_zcis", "y20_infl", "y30_zcis"

I accomplished something similar with the extremely ugly:

$ cat in.txt | sed 's/ /\'$'\n/g' | sed 's/\(.*\)/"\1",/g' | tr -d '\n'


"y10_zcis","y10_nom","y10_infl","y20_zcis","y20_infl","y30_zcis",

But that feels like an utter failure, and it doesn't take care of the last unwanted , (but perhaps this is best to just delete afterwards)

Best Answer

You can do

sed -e 's| |", "|g' -e 's|^|"|g' -e 's|$|"|g' in.txt

Where

's| |", "|g' will replace every space with ", "
's|^|"|g' while at the beginning there's no space, you must specify with ^ the beginning of the line, so you're telling, put " at the beginning.
's|$|"|g' same thing but specifying the end of every line with $

UPDATE

As @don_crissti pointed out, you can do it shorter with the following

sed 's| |", "|g;s|.*|"&"|'

Where

; separate each instruction
.* matches the entire line.
& an ampersand on the RHS is replaced by the entire expression matched on the LHS, in this case .*

RHS=Right hand side

LHS=Left hand side

Related Solutions

Lum – How to sed output be formatted like printf’s formatted printing

This uses the extended regex syntax -r, which clears up a lot of the clutter. Also, because you already know some of the field values, you don't actually need to back-reference them, again reducing clutter (and overhead).

& is a special replacement value: it hold the entire matched pattern. Using the &, again reduces clutter. As it is not a back-reference, it has significantly less overhead.

I've used ( +) vs. ( *). The + assumes that there is at least one space between input fields. Just change it to the * it that is not the case.

EXPL=
dom=oracle
typ=hard
itm=nproc
val=666

echo "oracle   hard   nproc    131072" |
  sed -r "s/^$dom( +)$typ( +)$itm( +).*/$EXPL#&\n$dom\1$typ\2$itm\3$val/"

output

#oracle   hard   nproc    131072
oracle   hard   nproc    666

Shell – How to write a sed script to delete numbers from a line

Given this input, you want to keep the first and last fields. Pretty simple with awk:

awk '{print $1, $NF}' filename

Using sed, this will replace all space delimited digit-only words:

sed ':a; s/ [[:digit:]]\+ / /; ta'

Best Answer

Related Solutions

Lum – How to sed output be formatted like printf’s formatted printing

Shell – How to write a sed script to delete numbers from a line

Related Question