Best way to replace a single line with a variable containing symbols

Question

I have to insert a textblock into multiple (> 200) html files. I decided to address the assignment using bash.

The textblock that has to be inserted is a multiliner:

textblockvar='
 <body class="article toc2 toc-right">
 <div id="readspeaker-button1" class="rs_skip rsbtn rs_preserve"> 
 <a rel="nofollow" class="rsbtn_play" accesskey="L" title="Read 
 out with ReadSpeaker" href="//app-eu.readspeaker.com/cgi-bin
 /rsent?customerid=5&lang=nl_nl&amp;voice=Ilse&re$ 
 <span class="rsbtn_left rsimg rspart"><span 
 class="rsbtn_text"><span>Lees voor</span></span></span> 
 <span class="rsbtn_right rsimg rsplay rspart"></span> 
 </a> 
 </div>
 '

The textblockvar will replace the <body class="article toc2 toc-right"> tag, that seems to be consistent in all 200+ html files.

I tried various techniques to execute the substitution:

FILES=leerstof/*/*.html
for f in $FILES
do

 sed -e "s|'<body class="article toc2 toc-right"'|${textblockvar}|g" $f

done

However, the script always ends up with a fatal error: "unterminated `s' command".

I tried to exchange quotes, tried without quotes, but still the error persists.

Maybe my solution is not the best option. Are there any workarounds available?

Don't parse HTML with regular expressions! Use an HTML parser instead — Ruslan Osmanov, Jan 06 '17 at 03:14
Are you supposed to do this assignment in bash, or using an external scripting tool like sed or awk? (Also, [don't parse HTML with regular expressions](http://stackoverflow.com/a/1732454/1072112), like the man said!) — ghoti, Jan 06 '17 at 03:17
@ghoti I use bash scripting for this task. In the script I use sed for html replacement — kzpm, Jan 06 '17 at 09:55
I suspect your problem here is the use of double quotes (`"`). This character has a special meaning for shell. Then the arguments of your `sed` command are actually very different than expected. Use back slash to escape double quotes. — Jdamian, Jan 06 '17 at 13:04
kzpm, okay then, if your question is "How do I solve this problem the wrong way", I'll just move on to the next question. Good luck! :-) — ghoti, Jan 06 '17 at 13:23

score 0 · Answer 1 · answered Jan 08 '17 at 10:02

here is a way that might work:

quote your sed command with ', not ".
replace the newlines in your string variable with \n.
escape any ampersands in your replacement string, e.g., ...id=5\&lang=nl_nl\&voice=Ilse\&re...
use sed -i to change files in place.

e.g.,

textblockvar='<body class="article toc2 toc-right">\n<div id...'
...
sed -i 's|<body class="article toc2 toc-right"|'$textblockvar'|g' $f

note: test it without the -i first to just output what it would do and check if it works as intended. if it does, then use -i to actually change the files.

Best way to replace a single line with a variable containing symbols

1 Answers1