I am learning regular expression in sed,Please help me understand the use curly bracket in sed,
I am learning SED and just following the shell scripting book, i have trouble understanding the grep and sed statement,
Question : 1
__________
To my understanding , the above select will look for the number between 0 to 9 which should no exceed character 10.
If my above statement correct, then i should get the 8 digit mobile number in below select statement, but i am getting 10 and 8 digit number. it suppose to look for 0 to 9 and give 8 digit mobile number. please correct me if i am wrong.
Question 2
-----------
From the above select statement,
1. i am not able to understand what is the use of curly brackets?
2. \{2,3\}w/p' - what does each argument meant for ?
3. what is the use of w,{2,3\}?
Please explain
Thanks
Antony Ankrose J
Last edited by Antony Ankrose; 06-04-2014 at 04:03 PM..
Reason: Please use [code][/code] tags.
To my understanding , the above select will look for the number between 0 to 9 which should no exceed character 10.
It will look for exactly 10 digits in a row.
These exact 10 digits can appear anywhere in the line.
Quote:
If my above statement correct, then i should get the 8 digit mobile number in below select statement, but i am getting 10 and 8 digit number. it suppose to look for 0 to 9 and give 8 digit mobile number. please correct me if i am wrong.
It will find 8 digits inside 10 digits, the same way it will find 'gas' inside 'gasoline'.
To find only 8 digits you must be more specific. Perhaps
to tell it there must be a space in front, and that the string must end at the end of the line.
Still i am not able to get you completely what you say
^ Matches the beginning of lines.
. Matches any single character.
Which means the command matches any character in the beginning of the line followed by any single character and then followed by checking any character between 2 or 3
in the first column and not able to get what this w for ?
Still i am not able to get you completely what you say
^ Matches the beginning of lines.
. Matches any single character.
Which means the command matches any character in the beginning of the line followed by any single character and then followed by checking any character between 2 or 3
No, it matches 2 or 3 of "any character". It'd match AB, QRZ, --, or anything that's two or three characters long.
So basically, this regex means "the third or fourth character must be a w".
Quote:
not able to get what this w for?
The letter "w" in the regex matches the letter "w" in the string.
Hi , I need to remove pipe character from a |^ delimeted file.
Something like |^tran|sformers||^|revenge |of fallen|^ to
|^transformers|^revenge of fallen|^...
Cold anybody please help to build the regular expression using sed .
many thanks.
Please use code tags next time for... (1 Reply)
Hello All,
I'm trying to extract the lines between two consecutive elements of an array from a file.
My array looks like:
problem_arr=(PRS111 PRS213 PRS234)
j=0
while } ]
do
k=`expr $j + 1`
sed -n "/${problem_arr}/,/${problem_arr}/p" problemid.txt
---some operation goes... (11 Replies)
Hi all,
I want to get a substring from a string based on given delimiter, for example:
str="foo|bar|baz" with delimiter "|",
I want to get one substring at each time with the order number the substring in the whole string,
given 1 to get "foo",
given 2 to get "bar",
given 3 to get "baz",
I... (2 Replies)
Hi ,
I am learing sed
echo abc 123 def 456 | sed 's|\(*\) \(*\)|\1|'
is returning abc def 456
i was hoping abc def "\1" should only print the occurence of the first pattern
but according to my understanding it is just removing the first occurence of the second pattern... (7 Replies)
please consider this:
echo "11111*X*005010X279~ST*270*1111111*005010X279~BHT*0011*11" | sed 's/.*\(005010X(\d)(\d)(\d)*\).*$/\1/'i'm searching for first occurrence of 005010X while leaving rest of characters out.
:confused:
any tips? thnx in advance guys. (7 Replies)
Hi
I need to get text that are within ""
For example
File:
asdasd "test test2" sadasds asdda asdasd "demo demo2"
Output:
test test2 demo demo2
Any help is good
Thank you (12 Replies)
Hello,
I would like to replace Line 187 of my file named run_example.
The original line is below, including the spaces:
celldm(1) = 6.00,
I want it to become something like
celldm(1) = 6.05,
or
celldm(1) = 6.10,
where the number is stored in a variable called... (6 Replies)
Hi!
I'm trying to write a regexp but I have no luck...
I have a string like this:
param1=sometext¶m2=hello¶m3=bye
Also, the string can be simply:
param2=hello
I want to return the value of param2: "hello".
How can I do this?
Thanks. (3 Replies)
Hi,
I'm trying following:echo "test line XA24433 test" | sed 's/.*X\(.*\)/X\1/'
XA24433 test While I want the output as: XA24433
I want to grab the words starting with letter X till the next space, this word can be anywhere in the line. (9 Replies)