I am trying replace a block of code between two patterns with blank lines
Tried using below command
sed '/PATTERN-1/,/PATTERN-2/d' input.pl
But it only removes the lines between the patterns
PATTERN-1 : "=head"
PATTERN-2 : "=cut"
input.pl contains below text
=head
hello
hello world
world
morning
gud
=cut
Required output :
=head
=cut
Can anyone help me on this?
$ awk '/=cut/{f=0} {print (f ? "" : $0)} /=head/{f=1}' file
=head
=cut
To modify the given sed command, try
$ sed '/=head/,/=cut/{//! s/.*//}' ip.txt
=head
=cut
//! to match other than start/end ranges, might depend on sed implementation whether it dynamically matches both the ranges or statically only one of them. Works on GNU sed
s/.*// to clear these lines
awk '/=cut/{found=0}found{print "";next}/=head/{found=1}1' infile
# OR
# ^ to take care of line starts with regexp
awk '/^=cut/{found=0}found{print "";next}/^=head/{found=1}1' infile
Explanation:
awk '/=cut/{ # if line contains regexp
found=0 # set variable found = 0
}
found{ # if variable found is nonzero value
print ""; # print ""
next # go to next line
}
/=head/{ # if line contains regexp
found=1 # set variable found = 1
}1 # 1 at the end does default operation
# print current line/row/record
' infile
Test Results:
$ cat infile
=head
hello
hello world
world
morning
gud
=cut
$ awk '/=cut/{found=0}found{print "";next}/=head/{found=1}1' infile
=head
=cut
This might work for you (GNU sed):
sed '/=head/,/=cut/{//!z}' file
Zap the lines between =head and =cut.
Related
I have a file with text as follows:
###interest1 moreinterest1### sometext ###interest2###
not-interesting-line
sometext ###interest3###
sometext ###interest4### sometext othertext ###interest5### sometext ###interest6###
I want to extract all strings between ### .
My desired output would be something like this:
interest1 moreinterest1
interest2
interest3
interest4
interest5
interest6
I have tried the following:
grep '###' file.txt | sed -e 's/.*###\(.*\)###.*/\1/g'
This almost works but only seems to grab the first instance per line, so the first line in my output only grabs
interest1 moreinterest1
rather than
interest1 moreinterest1
interest2
Here is a single awk command to achieve this that makes ### field separator and prints each even numbered field:
awk -F '###' '{for (i=2; i<NF; i+=2) print $i}' file
interest1 moreinterest1
interest2
interest3
interest4
interest5
interest6
Here is an alternative grep + sed solution:
grep -oE '###[^#]*###' file | sed -E 's/^###|###$//g'
This assumes there are no # characters in between ### markers.
With GNU awk for multi-char RS:
$ awk -v RS='###' '!(NR%2)' file
interest1 moreinterest1
interest2
interest3
interest4
interest5
interest6
You can use pcregrep:
pcregrep -o1 '###(.*?)###' file
The regex - ###(.*?)### - matches ###, then captures into Group 1 any zero o more chars other than line break chars, as few as possible, and ### then matches ###.
o1 option will output Group 1 value only.
See the regex demo online.
sed 't x
s/###/\
/;D; :x
s//\
/;t y
D;:y
P;D' file
Replacing "###" with newline, D, then conditionally branching to P if a second replacement of "###" is successful.
This might work for you (GNU sed):
sed -n 's/###/\n/g;/[^\n]*\n/{s///;P;D}' file
Replace all occurrences of ###'s by newlines.
If a line contains a newline, remove any characters before and including the first newline, print the details up to and including the following newline, delete those details and repeat.
I have a problem with replacing string.
|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631
I want to find occurrence of Svc till | appears and swap place with Stm till | appears.
My attempts went to replacing characters and this is not my goal.
awk -F'|' -v OFS='|'
'{a=b=0;
for(i=1;i<=NF;i++){a=$i~/^Stm=/?i:a;b=$i~/^Svc=/?i:b}
t=$a;$a=$b;$b=t}7' file
outputs:
|Svc=101|Seq=2|Num=2|Stm=2|MsgSize(514)=514|MsgType=556|SymbolIndex=16631
the code exchange the column of Stm.. and Svc.., no matter which one comes first.
If perl solution is okay, assumes only one column matches each for search terms
$ cat ip.txt
|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631
$ perl -F'\|' -lane '
#i = grep { $F[$_] =~ /Svc|Stm/ } 0..$#F;
$t=$F[$i[0]]; $F[$i[0]]=$F[$i[1]]; $F[$i[1]]=$t;
print join "|", #F;
' ip.txt
|Svc=101|Seq=2|Num=2|Stm=2|MsgSize(514)=514|MsgType=556|SymbolIndex=16631
-F'\|' -lane split input line on |, see also Perl flags -pe, -pi, -p, -w, -d, -i, -t?
#i = grep { $F[$_] =~ /Svc|Stm/ } 0..$#F get index of columns matching Svc and Stm
$t=$F[$i[0]]; $F[$i[0]]=$F[$i[1]]; $F[$i[1]]=$t swap the two columns
Or use ($F[$i[0]], $F[$i[1]]) = ($F[$i[1]], $F[$i[0]]); courtesy How can I swap two Perl variables
print join "|", #F print the modified array
You need to use capture groups and backreferences in a string substition.
The below will swap the 2:
echo '|Stm=2|Seq=2|Num=2|Svc=101|MsgSize(514)=514|MsgType=556|SymbolIndex=16631' | sed 's/\(Stm.*|\)\(.*\)\(Svc.*|\)/\3\2\1/'
As pointed out in the comment from #Kent, this will not work if the strings were not in that order.
I try to use sed to replace a word in a 2-line pattern with another word. When in one line the pattern 'MACRO "something"' is found then in the next line replace 'BLOCK' with 'CORE'. The "something" is to be put into a reference and printed out as well.
My input data:
MACRO ABCD
CLASS BLOCK ;
SYMMETRY X Y ;
Desired outcome:
MACRO ABCD
CLASS CORE ;
SYMMETRY X Y ;
My attempt in sed so far:
sed 's/MACRO \([A-Za-z0-9]*\)/,/ CLASS BLOCK ;/MACRO \1\n CLASS CORE ;/g' input.txt
The above did not work giving message:
sed: -e expression #1, char 30: unknown option to `s'
What am I missing?
I'm open to one-liner solutions in perl as well.
Thanks,
Gert
Using a perl one-liner in slurp mode:
perl -0777 -pe 's/MACRO \w+\n CLASS \KBLOCK ;/CORE ;/g' input.txt
Or using a streaming example:
perl -pe '
s/^\s*\bCLASS \KBLOCK ;/CORE ;/ if $prev;
$prev = $_ =~ /^MACRO \w+$/
' input.txt
Explanation:
Switches:
-0777: Slurp files whole
-p: Creates a while(<>){...; print} loop for each line in your input file.
-e: Tells perl to execute the code on command line.
When in one line the pattern 'MACRO "something"' is found then in the
next line replace 'BLOCK' with 'CORE'.
sed works on lines of input. If you want to perform substitution on the next line of a specified pattern, then you need to add that to the pattern space before being able to do so.
The following might work for you:
sed '/MACRO/{N;s/\(CLASS \)BLOCK/\1CORE/;}' filename
Quoting from the documentation:
`N'
Add a newline to the pattern space, then append the next line of
input to the pattern space. If there is no more input then sed
exits without processing any more commands.
If you want to make use of address range as in your attempt, then you need:
sed '/MACRO/,/CLASS BLOCK/{s/\(CLASS\) BLOCK/\1 CORE/}' filename
I'm not sure why do you need a backreference for substituting the macro name.
You could try this awk command also,
awk '{print}/MACRO/ {getline; sub (/BLOCK/,"CORE");{print}}' file
It prints all the lines as it is and do the replacing action on seeing a word MACRO on a line.
Since getline has so many pitfall I try not to use it, so:
awk '/MACRO/ {a++} a==1 {sub(/BLOCK/,"CORE")}1' file
MACRO ABCD
CLASS CORE ;
SYMMETRY X Y ;
This could do it
#!awk -f
BEGIN {
RS = ";"
}
/MACRO/ {
sub("BLOCK", "CORE")
}
{
printf s++ ? ";" $0 : $0
}
"line" ends with ;
sub BLOCK for CORE in "lines" with MACRO
print ; followed by "line" unless first line
I have a special file with this kind of format :
title1
_1 texthere
title2
_2 texthere
I would like all newlines starting with "_" to be placed as a second column to the line before
I tried to do that using sed with this command :
sed 's/_\n/ /g' filename
but it is not giving me what I want to do (doing nothing basically)
Can anyone point me to the right way of doing it ?
Thanks
Try following solution:
In sed the loop is done creating a label (:a), and while not match last line ($!) append next one (N) and return to label a:
:a
$! {
N
b a
}
After this we have the whole file into memory, so do a global substitution for each _ preceded by a newline:
s/\n_/ _/g
p
All together is:
sed -ne ':a ; $! { N ; ba }; s/\n_/ _/g ; p' infile
That yields:
title1 _1 texthere
title2 _2 texthere
If your whole file is like your sample (pairs of lines), then the simplest answer is
paste - - < file
Otherwise
awk '
NR > 1 && /^_/ {printf "%s", OFS}
NR > 1 && !/^_/ {print ""}
{printf "%s", $0}
END {print ""}
' file
This might work for you (GNU sed):
sed ':a;N;s/\n_/ /;ta;P;D' file
This avoids slurping the file into memory.
or:
sed -e ':a' -e 'N' -e 's/\n_/ /' -e 'ta' -e 'P' -e 'D' file
A Perl approach:
perl -00pe 's/\n_/ /g' file
Here, the -00 causes perl to read the file in paragraph mode where a "line" is defined by two consecutive newlines. In your example, it will read the entire file into memory and therefore, a simple global substitution of \n_ with a space will work.
That is not very efficient for very large files though. If your data is too large to fit in memory, use this:
perl -ne 'chomp;
s/^_// ? print "$l " : print "$l\n" if $. > 1;
$l=$_;
END{print "$l\n"}' file
Here, the file is read line by line (-n) and the trailing newline removed from all lines (chomp). At the end of each iteration, the current line is saved as $l ($l=$_). At each line, if the substitution is successful and a _ was removed from the beginning of the line (s/^_//), then the previous line is printed with a space in place of a newline print "$l ". If the substitution failed, the previous line is printed with a newline. The END{} block just prints the final line of the file.
I need help with using sed to comment a matching lines and 4 lines which follows it.
in a text file.
my text file is like this:
[myprocess-a]
property1=1
property2=2
property3=3
property4=4
[anotherprocess-b]
property1=gffgg
property3=gjdl
property2=red
property4=djfjf
[myprocess-b]
property1=1
property4=4
property2=2
property3=3
I want to prefix # to all the lines having text '[myprocess' and 4 lines that follows it
expected output:
#[myprocess-a]
#property1=1
#property2=2
#property3=3
#property4=4
[anotherprocess-b]
property1=gffgg
property3=gjdl
property2=red
property4=djfjf
#[myprocess-b]
#property1=1
#property4=4
#property2=2
#property3=3
Greatly appreciate your help on this.
You can do this by applying a regular expression to a set of lines:
sed -e '/myprocess/,+4 s/^/#/'
This matches lines with 'myprocess' and the 4 lines after them. For those 4 lines it then inserts a '#' at the beginning of the line.
(I think this might be a GNU extension - it's not in any of the "sed one liner" cheatsheets I know)
sed '/\[myprocess/ { N;N;N;N; s/^/#/gm }' input_file
Using string concatenation and default action in awk.
http://www.gnu.org/software/gawk/manual/html_node/Concatenation.html
awk '/myprocess/{f=1} f>5{f=0} f{f++; $0="#" $0} 1' foo.txt
or if the block always ends with empty line
awk '/myprocess/{f=1} !NF{f=0} f{$0="#" $0} 1' foo.txt