Suppose I have following string. I want to replace <b>2</b> to <b>20</b> if <a>2</a>
<start>
<a>1</a><b>1</b>
<a>2</a><b>2</b>
.
.
<a>10</a><b>10</b>
<a>2</a><b>2</b>
</start>
New string should look like this
<start>
<a>1</a><b>1</b>
<a>2</a><b>20</b>
.
.
<a>10</a><b>10</b>
<a>2</a><b>20</b>
</start>
can I do this using sed?
You can start with this:
sed '/<start>/,/<\/start>/s!\(<a>2</a><b>2\)</b>!\10</b>!' input
and relax the expression as required, for example allow spaces in tag a:
sed '/<start>/,/<\/start>/{/<a>[ ]*2[ ]*<\/a>/s!<b>2<!<b>20<!}' input
This will replace the first occurrence of <b>2</b> with <b>20</b> in all the lines with <a>2</a> invoke:
sed '/<a>2<\/a>/s/<b>2<\b>/<b>20<\/b>/' input
Related
I have the following string:
signal[i]
signal[bg]
output [10:0]
input [i:1]
what I want is to replace the letters between square brackets (by underscore for example) and to keep the other strings that represents table declaration:
signal[_]
signal[__]
output [10:0]
input [i:1]
thanks
try:
awk '{gsub(/\[[a-zA-Z]+\]/,"[_]")} 1' Input_file
Globally substituting the (bracket)alphabets till their longest match then with [_]. Mentioning 1 will print the lines(edited or without edited ones).
EDIT: Above will substitute all alphabets with one single _, so to get as many underscores as many characters are there following may help in same.
awk '{match($0,/\[[a-zA-Z]+\]/);VAL=substr($0,RSTART+1,RLENGTH-2);if(VAL){len=length(VAL);;while(i<len){q=q?q"_":"_";i++}};gsub(/\[[a-zA-Z]+\]/,"["q"]")}1' Input_file
OR
awk '{
match($0,/\[[a-zA-Z]+\]/);
VAL=substr($0,RSTART+1,RLENGTH-2);
if(VAL){
len=length(VAL);
while(i<len){
q=q?q"_":"_";
i++
}
};
gsub(/\[[a-zA-Z]+\]/,"["q"]")
}
1
' Input_file
Will add explanation soon.
EDIT2: Following is the one with explanation purposes for OP and users.
awk '{
match($0,/\[[a-zA-Z]+\]/); #### using match awk's built-in utility to match the [alphabets] as per OP's requirement.
VAL=substr($0,RSTART+1,RLENGTH-2); #### Creating a variable named VAL which has substr($0,RSTART+1,RLENGTH-2); which will have substring value, whose starting point is RSTART+1 and ending point is RLENGTH-2.
RSTART and RLENGTH are the variables out of the box which will be having values only when awk finds any match while using match.
if(VAL){ #### Checking if value of VAL variable is NOT NULL. Then perform following actions.
len=length(VAL); #### creating a variable named len which will have length of variable VAL in it.
while(i<len){ #### Starting a while loop which will run till the value of VAL from i(null value).
q=q?q"_":"_"; #### creating a variable named q whose value will be concatenated it itself with "_".
i++ #### incrementing the value of variable i with 1 each time.
}
};
gsub(/\[[a-zA-Z]+\]/,"["q"]") #### Now globally substituting the value of [ alphabets ] with [ value of q(which have all underscores in it) then ].
}
1 #### Mentioning 1 will print (edited or non-edited) lines here.
' Input_file #### Mentioning the Input_file here.
Alternative gawk solution:
awk -F'\\[|\\]' '$2!~/^[0-9]+:[0-9]$/{ gsub(/./,"_",$2); $2="["$2"]" }1' OFS= file
The output:
signal[_]
signal[__]
output [10:0]
-F'\\[|\\]' - treating [ and ] as field separators
$2!~/^[0-9]+:[0-9]$/ - performing action if the 2nd field does not represent table declaration
gsub(/./,"_",$2) - replace each character with _
This might work for you (GNU sed);
sed ':a;s/\(\[_*\)[[:alpha:]]\([[:alpha:]]*\]\)/\1_\2/;ta' file
Match on opening and closing square brackets with any number of _'s and at least one alpha character and replace said character by an underscore and repeat.
awk '{sub(/\[i\]/,"[_]")sub(/\[bg\]/,"[__]")}1' file
signal[_]
signal[__]
output [10:0]
input [i:1]
The explanation is as follows: Since bracket is as special character it has to be escaped to be handled literally then it becomes easy use sub.
I have a text file including lines in the form of:
(term1 x:a y:b (term2 z:c k:a))
I want to extract only terms from this line using command line utilities such as awk, grep, sed. i.e I want the result to be:
term1
term2
I have formed a regex matching the rest but the terms, but could not find a way to negate it.
(\()|( \()|( (.*?) \()|( (.*?)\)+)
How can I form a command extracting the every substring after '(' and before ' '?
Thanks
Try this:
sed "s/(\([^ (]*\)[^(]*/\1\n/g"
For example:
$ echo "(term1 x:a y:b (term2 (term3) z:c k:a) x (termX a:b ) )" | sed "s/(\([^ )]*\)[^(]*/\1\n/g"
term1
term2
term3
termX
I am having difficulties replacing a string containing special characters using sed. My old and new string are shown below
oldStr = "# td=(nstates=20) cam-b3lyp/6-31g geom=connectivity"
newStr = "# opt b3lyp/6-31g geom=connectivity"
My sed command is the following
sed -i 's/\# td\=\(nstates\=20\) cam\-b3lyp\/6\-31g geom\=connectivity/\# opt b3lyp\/6\-31g geom\=connectivity/g' myfile.txt
I dont get any errors, however there is no match. Any ideas on how to fix my patterns.
Thanks
try s|# td=(nstates=20) cam-b3lyp/6-31g geom=connectivity|# opt b3lyp/6-31g geom=connectivity|g'
you can use next to anything after s instead of /, as your expression contains slashes I used | instead. -, = and # don't have to be escaped (minus only in character sets [...]), escaped parens indicate a group, nonescaped parens are literals.
Hi I want to replace a string coming between to symbols by using sed
example: -amystring -bxyz
what to replace mystring with ****
value after -a can be anything like -amystring 123 -bxyz, -amystring 123<newline_char>, -a'mystring 123' -bxyz, -a'mystring 123'<newline_char>
I tried following regex but it does not work in all the cases
sed -re "s#(-w)([^\s\-]+)#\1**** #g"
can anybody help me to solve this issue ?
MyString="YourStringWithoutRegExSpecialCharNotEscaped"
sed "s/-a${MyString} -b/-a**** -b/g"
if you can escape your string for any regex key char like * + . \ / with something like
echo "${MyString}" | sed 's/\[*.\\/+?]/\\&/g' | read -r MyString
before us it in sed.
otherwise, you need to better define the edge pattern
I am trying to write a script to take all the php.js functions and create a node.js library for them, Which means I have to figure out how to convert
this
function key (arr) {
to
key: function (arr) {
I know sed can do it, But I can't figure it out
Thanks for any help
sed 's/function\s\(.*\)(/\1: function(/g' file.js
That should do the trick
Here is an awk to swap fields
awk '/function/ {t=$2":";$2=$1;$1=t} 1' file.js
key: function (arr) {
sed "s/^ *function \{1,\}\([^ ]\{1,\}\) \{1,\}(/\1: function (/" file.js
replace the \s by " " assuming there is not tab in white space of the code