Clever Geek Handbook

Add character on next n non-blank lines after regex in bash

I have a config file that contains the following lines and would like to know how to add ';' at the beginning of each line after the [treadmill] until the next blank line. I would like to do it with a script as these lines should be included depending on the configuration of this environment.

[treadmill]
type = aor
contact = server.domain.com

[A_SRV]
type = aor
contact = serverA.domain.com

[B_SRV]
type = aor
contact = serverB.domain.com

[treadmill]
type = identify
endpoint = treadmill
match = server.domain.com

[C_SRV_IDEN]
type = identify
endpoint = sip
match = server.domain.com

[treadmill]
type = endpoint
context = LocalSets
dtmf_mode = rfc4733
disallow = all
allow = ulaw
direct_media = no
aors = treadmill
+3


source to share


3 answers


sed -e '/\[treadmill\]/,/^$/{//!s/^/;/}' treadmill.txt

Explanation:

  • /\[treadmill\]/,/^$/

    uses the syntax /START/,/END/

    to apply subsequent commands in curly braces {}

    in the range START to END, including the START and END lines. /^$/

    a completely empty string is required, no spaces.

  • {//!s/^/;/}

    - one command in curly braces applied in the above range.

  • //!

    means that "does not match the previous match" because it //

    is a previous match. This prevents START and END lines from being processed.

  • //!s/^/;/

    binds the replacement s/^/;/

    to strings where //!

    true. This adds a semicolon to every line between START and END

  • My initial suggestion for a semicolon skeleton was s/.*/;&/

    - this replaces .*

    with ;&

    , where &

    on the replacement side matches any .*

    . As @WilliamPursell commented, this is potentially less clear thans/^/;/

  • In some shells, this !

    is a special character that also needs to be flushed back. In bash, it should be fine.


Output:

[treadmill]
;type = aor
;contact = server.domain.com

[A_SRV]
type = aor
contact = serverA.domain.com

[B_SRV]
type = aor
contact = serverB.domain.com

[treadmill]
;type = identify
;endpoint = treadmill
;match = server.domain.com

[C_SRV_IDEN]
type = identify
endpoint = sip
match = server.domain.com

[treadmill]
;type = endpoint
;context = LocalSets
;dtmf_mode = rfc4733
;disallow = all
;allow = ulaw
;direct_media = no
;aors = treadmill
+1


source


With awk



awk '!NF { f = 0 }
         { print (f == 1 ? ";" : "") $0 }
     $0 ~ /^\[treadmill\]$/
         { f = 1 }
' file
0


source


It's pretty confusing, but it actually works.

grep -ne "^\[treadmill\]" $DIRPATH/pjsip.conf.sample | cut -d : -f 1 | awk '{print $1" on"}' > lines.txt
grep -n '^$' $DIRPATH/pjsip.conf.sample | cut -d : -f 1 | awk '{print $1" off"}' >> lines.txt
cat lines.txt | sort -n > lines2.txt

IFS=$'\n'       # make newlines the only separator

declare -i arr4
items=0

for i in $(cat lines2.txt) ; do
    SWITCH=`echo $i | cut -d' ' -f 2`
    LINE=`echo $i | cut -d' ' -f 1`
    if [ "$SWITCH" = "on" ] && [ $SWITCHED -eq 0 ]; then
        SWITCHED=1
        arr4[$items]=$LINE
        ((++items))
    fi
    if [ "$SWITCH" = "off" ] && [ $SWITCHED -eq 1 ]; then
        SWITCHED=0
        arr4[$items]=$LINE
        ((++items))
    fi

done

count=${#arr4[@]}

let SECTIONS=$count/2
let SECTIONS-=1

for i in `seq 0 $SECTIONS` ; do
    let START=$((arr4[$i*2]))
    let END=$((arr4[($i*2)+1]))-1
    for j in `seq ${START} ${END}` ; do
        sed -i "$j s/^/;/" $DIRPATH/pjsip.conf.sample
    done
done

rm lines.txt lines2.txt
0


source






More articles:


All Articles