Insert multiple lines of text before specific line

问题:

I am trying to insert a few lines of text before a specific line, but keep getting sed errors when I try to add a new line character. My command looks like:

sed -r -i '/Line to insert after/ i Line one to insert \\
    second new line to insert \\
    third new line to insert' /etc/directory/somefile.txt

The error that is reported is:

sed: -e expression #1, char 77: unterminated `s' command

I've tried, using \n, \\ (as in the example), no character at all, just moving the second line to the next line. I've also tried something like:

sed -r -i -e '/Line to insert after/ i Line one to insert'
    -e 'second new line to insert'
    -e 'third new line to insert' /etc/directory/somefile.txt

EDIT!: Apologies, I wanted the text inserted BEFORE the existing, not after!

回答1:

This should work:

sed -i '/Line to insert after/ i Line one to insert \
second new line to insert \
third new line to insert' file

回答2:

For anything other than simple substitutions on individual lines, use awk instead of sed for simplicity, clarity, robustness, etc., etc.

To insert before a line:

awk '
/Line to insert before/ {
    print "Line one to insert"
    print "second new line to insert"
    print "third new line to insert"
}
{ print }
' /etc/directory/somefile.txt

To insert after a line:

awk '
{ print }
/Line to insert after/ {
    print "Line one to insert"
    print "second new line to insert"
    print "third new line to insert"
}
' /etc/directory/somefile.txt

回答3:

When the lines to be inserted are the result of some command "mycmd" (like cat results.txt or printf "%s\n" line{1..3}), you can do

sed -i 's/Line to insert after/r' <(cmd) file
or 
sed -i 's/Line to insert after/echo "&";cmd/e' file

The last command can be simple modified when you want to insert before some match.

回答4:

sed -i '/Line to insert after/ i\
Line one to insert\
second new line to insert\
third new line to insert' /etc/directory/somefile.txt

回答5:

This might work for you (GNU sed & Bash):

sed -i $'/Line to insert after/a\line1\\nline2\\nline3' file

回答6:

This ll works from the first line.. For eg: If you want to insert from 3rd line of a file, replace "1i" to "3i".

sed -i '1i line1'\\n'line2'\\n'line3' 1.txt 

cat 1.txt

 line1
 line2
 line3
 Hai

回答7:

To be POSIX compliant and run in OS X, I used the following (single quoted line and empty line are for demonstration purposes):

sed -i "" "/[pattern]/i\\
line 1\\
line 2\\
\'line 3 with single quotes\`
\\
" <filename>

回答8:

This can be easily done with Perl also

$ cat MeanwhileInHell.txt
Iran|XXXXXX|Iranian
Iraq|YYYYYY|Iraquian
Saudi|ZZZZZ|Saudi is a Rich Country
USA|AAAAAA|USA is United States of America.
India|IIII|India got freedom from British.
Scot|SSSSS|Canada Mexio.
$ perl -pe 'BEGIN {$x="Line one to insert\nLine 2\nLine3\n"} $_=$x.$_ if /USA/ ' MeanwhileInHell.txt
Iran|XXXXXX|Iranian
Iraq|YYYYYY|Iraquian
Saudi|ZZZZZ|Saudi is a Rich Country
Line one to insert
Line 2
Line3
USA|AAAAAA|USA is United States of America.
India|IIII|India got freedom from British.
Scot|SSSSS|Canada Mexio.
$