Replace a word with multiple lines using sed?

Question

I'm working on a bash-script that has to prepare an E-Mail for being sent to a user.

It aggregates some data, which ends up being multiple lines of stuff. For the example stored in $DATA .

Now, after a bit of stfw I found a few things like sed -ei "s/_data_/${DATA}/g" mail.tpl and also sed replace with variable with multiple lines . None of them work.

Now the question is, how do I get sed to replace something with multiple lines of text?

(Alternatives to sed are also welcome!)

Answer 1

You can do this with AWK using variable substitution. We can set a variable in AWK using -v , and then use AWK's gsub function to substitute all occurrences of a regular expression with that variable.

For example, if the file test has the following contents ...

foo
bar
blah _data_and_data_
foo
_data_ foobar _data_ again

... and the Bash variable $DATA is ...

1
2
3
4
5

... then awk -vr=$DATA '{gsub(/_data_/,r)}1' test replaces all occurrences of the regular expression _data_ in the file test with the contents of $DATA , resulting in the following:

foo
bar
blah 1
2
3
4
5and1
2
3
4
5
foo
1
2
3
4
5 foobar 1
2
3
4
5 again

Answer 2

我建议简单地将 sed 替换为 perl 命令，如下所示：

perl -i.bak -pe 's/_data_/$ENV{"DATA"}/g' mail.tpl 

Answer 3

If you build your multiple line text with " \n "s, this will work with a simple sed command as:

DATA=`echo ${DATA} | tr '\n' "\\n"`
#now, DATA="line1\nline2\nline3"
sed "s/_data_/${DATA}/" mail.tpl

Answer 4

I tried it and sed 's/pattern/\na\nb\nc/g' but it does not work on all systems. What does work is putting a \ followed by a newline in the replace pattern, like this:

sed 's/pattern/a\
b\
c/g'

This appends a line containing b and a line containing c when the pattern is seen.

To put it in a variable, use double backslashes:

export DATA="\\
a\\
b\\
c"

and then:

sed "s/pattern/${DATA}/g"

Note the double quotes.

Answer 5

ring bearer's answer didn't work for me; I think the usage of tr there is wrong, and the way it's written, it simply strips away newlines by use of echo .

Instead, I used sed . I used code from another answer to replace newlines (credit: Zsolt Botykai). I also expected some dollar signs ( $ ) in my input so I took care of that too. You might need to add other input handling. Note the use of double quotes in echo to preserve newlines.

DATA="$(cat whatever)"
ESCAPED_DATA="$(echo "${DATA}" | sed ':a;N;$!ba;s/\n/\\n/g' | sed 's/\$/\\$/g')"

Then you can use ${ESCAPED_DATA} in sed :

cat input | sed 's/one liner/'"${ESCAPED_DATA}"'/' > output 

Just thought I'd share.

Answer 6

Echo variable into temporary text file.

Insert text file into mail.tpl and delete data from mail.tpl

echo ${DATA} > temp.txt    
sed -i -e "/_data_/r temp.txt" -e "//d" mail.tpl

Answer 7

Escaping all the newlines with a \ (except the last one) worked for me. The last newline must not be escaped not to break the s command.

Example :

DATA="a
b
c"

ESCAPED=$(echo "${DATA}" | sed '$!s@$@\\@g')
echo "${ESCAPED}" 
a\
b\
c

sed "s/pattern/${ESCAPED}/" file

Answer 8

您可以将数据放在临时文件中并运行：

$ sed '/_data_/r DATA_FILE' mail.tpl | sed '/_data_/d'> temp; mv temp mail.tpl

Answer 9

Not sure if you have tried to put "\n" in the replace part

sed 's/[pattern]/\
[line 1]\n\
[line 2]\n\
[line n]\n\
/g' mail.tpl

The first line has /\ for readibility reasons. Each line after that is a stand-alone line like you would find in a text editor. Last line is stand-alone, once again for readability reasons. You can make all of this one line if needed. Works on Debian Jessie when I tested it.

Answer 10

As per the gnu documentation about multiline techniques :

sed '/./{H;$!d;}; x; s/REGEXP/REPLACEMENT/'

The first expression, /./{H;$;d;} operates on all non-empty lines, and adds the current line (in the pattern space) to the hold space. On all lines except the last, the pattern space is deleted and the cycle is restarted.

The x command fetches the accumulated lines from the hold space back to the pattern space.

The s/// command then operates on all the text in the paragraph (including the embedded newlines).

Answer 11

DATA=`echo ${DATA} | tr '\n' "\n"`

sed -z "s/_data_/${DATA}/g" -i mail.tpl

Try this...