remove last delimiter in sed/awk/perl - perl

An input file is given, each line of which contains delimited data with extra delimiter at the end in data/header with or without enclosures.
Extra delimiter at the end it can contain with/without spaces.
Scenario 1 : Header & Data contain extra delimiter at the end
eno|ename|address|
A|B|C|
D|E|F|
Scenario 2 : Header doesn't contain extra delimiter at the end
eno|ename|address
A|B|C|
D|E|F|
Scenario 3 : With enclosures
eno|ename|address|
1|2|"A"|
Final output has to be like
Scenario 1 :
eno|ename|address
A|B|C
D|E|F
Scenario 2 :
eno|ename|address
A|B|C
D|E|F
Scenario 3 :
eno|ename|address
1|2|"A"
Solution which i have tried so far. But below solution won't work for all three scenarios is there anyway which i can make single command to support all the three scenarios in Sed/Awk/Perl
perl -pne 's/(.*)\|/$1/' filename

Could you please try following.
awk '{gsub(/\|$|\| +$/,"")} 1' Input_file
Explanation:
gsub is awk function which Globally substitute matched pattern with mentioned value.
Explanation of regex:
/\|$|\| +$/: Here there are 2 parts of regex. First is /\|$ and second is +$ which is segrigated with | where 1st regex is for removing | from last of the line and second regex removes | with space at last. So it basically takes care of both conditions successfully.

perl -lpe 's/\|\s*$//' file
will do it. That only removes pipes followed by optional whitespace at the end of each line. Note the $ line anchor.
I added the -l since each line's newline will get removes by the s/// command, and -l will put it back.

All you need is this:
sed 's/|$//'

A bit more generic. Let's assume you have the same problem, but with different field separators in different files. Some of these field separators are regular expressions (e.g. a sequence of blanks), others are just a single character c. With a tiny little awk program you can get far:
# remove_last_empty_field.awk
# 1. Get the correct `fs`
BEGIN { fs=FS; if(length(FS)==1) fs=(FS==" ") ? "[[:blank:]]+" : "["FS"]" }
# remove the empty field
{ sub(fs"$","") }
# Print the current record
1
Now you can run this on your various files as:
$ awk -f remove_last_empty_field.awk f1.txt
$ awk -f remove_last_empty_field.awk FS="|" f2.txt
$ awk -f remove_last_empty_field.awk FS="[|.*]" f3.txt

perl -pi -e 's/\|$//' Your_FIle

Related

sed remove lines with any alphabetical order

im trying to remove all lines that have any 3 characters in alphabetical order with sed is there an easy way to do this instead of a bunch of pattern lines
sed -i '/abc/d
/bcd/d
....
/xyz/d' file.txt
With your attempted code, please try following awk code, where we are not writing all combinations of continuous alphabets. IMHO awk will be much efficient then sed here.
awk '
BEGIN{
FS=""
num=split("a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z",arr1,",")
for(i=1;i<=num;i++){ letters[arr1[i]]=i }
}
{
for(i=1;i<=NF;i++){
if(($i in letters) && ($(i+1) in letters) && ($(i+2) in letters)\
&& (letters[$i]+1==letters[$(i+1)]) && (letters[$i]+2==letters[$(i+2)])\
&& (letters[$(i+1)]+1==letters[$(i+2)])){
print $i $(i+1) $(i+2)
}
}
}
' Input_file
Explanation: Simple and detailed explanation for whole awk program would be:
Explanation of BEGIN block of awk program:
Creating field separator(FS) as NULL for all lines in awk so that each character could be compared to find out 3 consecutive occurrences of letters.
Then using split function of awk creating an array named arr1 where splitting all alphabets(small letters) into it with delimiter of , here.
Then starting a for loop till value of num(could be written as 26 also since number of alphabets are always fixed), where creating an array named letters which has index as alphabets and its value will be their place value(their number on which they occur, eg: for a it will be 1).
Explanation of main block of awk program:
Running a for loop from 1st field to till NF all fields of current line basically.
Then checking conditions there(basically checking if current field and next 2 fields are coming in letters array or not AND checking if their sequence is continuous or not).
If all conditions mentioned are met then printing current and next 2 fields(which will basically print 3 letters).
This might work for you (GNU sed):
sed -En '1{x;s/^/abcdefghijklmnopqrstuvwxyz/;x};G;/(...).*\n.*\1/!P' file
On the first line, introduce a literal alphabet in the hold space.
On each line, append the alphabet and using a three character back reference, compare it the the alphabet.
If there is a match, delete the line, otherwise, print the first line only.
N.B. The use of the -n turns off implicit printing and thus only when a match fails is the line printed.

GREP Print Blank Lines For Non-Matches

I want to extract strings between two patterns with GREP, but when no match is found, I would like to print a blank line instead.
Input
This is very new
This is quite old
This is not so new
Desired Output
is very
is not so
I've attempted:
grep -o -P '(?<=This).*?(?=new)'
But this does not preserve the second blank line in the above example. Have searched for over an hour, tried a few things but nothing's worked out.
Will happily used a solution in SED if that's easier!
You can use
#!/bin/bash
s='This is very new
This is quite old
This is not so new'
sed -En 's/.*This(.*)new.*|.*/\1/p' <<< "$s"
See the online demo yielding
is very
is not so
Details:
E - enables POSIX ERE regex syntax
n - suppresses default line output
s/.*This(.*)new.*|.*/\1/ - finds any text, This, any text (captured into Group 1, \1, and then any text again, or the whole string (in sed, line), and replaces with Group 1 value.
p - prints the result of the substitution.
And this is what you need for your actual data:
sed -En 's/.*"user_ip":"([^"]*).*|.*/\1/p'
See this online demo. The [^"]* matches zero or more chars other than a " char.
With your shown samples, please try following awk code.
awk -F'This\\s+|\\s+new' 'NF==3{print $2;next} NF!=3{print ""}' Input_file
OR
awk -F'This\\s+|\\s+new' 'NF==3{print $2;next} {print ""}' Input_file
Explanation: Simple explanation would be, setting This\\s+ OR \\s+new as field separators for all the lines of Input_file. Then in main program checking condition if NF(number of fields) are 3 then print 2nd field (where next will take cursor to next line). In another condition checking if NF(number of fields) is NOT equal to 3 then simply print a blank line.
sed:
sed -E '
/This.*new/! s/.*//
s/.*This(.*)new.*/\1/
' file
first line: lines not matching "This.*new", remove all characters leaving a blank line
second lnie: lines matching the pattern, keep only the "middle" text
this is not the pcre non-greedy match: the line
This is new but that is not new
will produce the output
is new but that is not
To continue to use PCRE, use perl:
perl -lpe '$_ = /This(.*?)new/ ? $1 : ""' file
This might work for you:
sed -E 's/.*This(.*)new.*|.*/\1/' file
If the first match is made, the line is replace by everything between This and new.
Otherwise the second match will remove everything.
N.B. The substitution will always match one of the conditions. The solution was suggested by Wiktor Stribiżew.

sed - Replace comma after first regex match

i m trying to perform the following substitution on lines of the general format:
BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109,07",DF,CCCCCCCCCCC, .......
as you see the problem is that its a comma separated file, with a specific field containing a comma decimal. I would like to replace that with a dot .
I ve tried this, to replace the first occurence of a pattern after match, but to no avail, could someone help me?
sed -e '/,"/!b' -e "s/,/./"
sed -e '/"/!b' -e ':a' -e "s/,/\./"
Thanks in advance. An awk or perl solution would help me as well. Here's an awk effort:
gawk -F "," 'substr($10, 0, 3)==3 && length($10)==12 { gsub(/,/,".", $10); print}'
That yielded the same file unchanged.
CSV files should be parsed in awk with a proper FPAT variable that defines what constitutes a valid field in such a file. Once you do that, you can just iterate over the fields to do the substitution you need
gawk 'BEGIN { FPAT = "([^,]+)|(\"[^\"]+\")"; OFS="," }
{ for(i=1; i<=NF;i++) if ($i ~ /[,]/) gsub(/[,]/,".",$i);}1' file
See this answer of mine to understand how to define and parse CSV file content with FPAT variable. Also see Save modifications in place with awk to do in-place file modifications like sed -i''.
The following sed will convert all decimal separators in quoted numeric fields:
sed 's/"\([-+]\?[0-9]*\)[,]\?\([0-9]\+\([eE][-+]\?[0-9]+\)\?\)"/"\1.\2"/g'
See: https://www.regular-expressions.info/floatingpoint.html
This might work for you (GNU sed):
sed -E ':a;s/^([^"]*("[^",]*"[^"]*)*"[^",]*),/\1./;ta' file
This regexp matches a , within a pair of "'s and replaces it by a .. The regexp is anchored to the start of the line and thus needs to be repeated until no further matches can be matched, hence the :a and the ta commands which causes the substitution to be iterated over whilst any substitution is successful.
N.B. The solution expects that all double quotes are matched and that no double quotes are quoted i.e. \" does not appear in a line.
If your input always follows that format of only one quoted field containing 1 comma then all you need is:
$ sed 's/\([^"]*"[^"]*\),/\1./' file
BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109.07",DF,CCCCCCCCCCC, .......
If it's more complicated than that then see What's the most robust way to efficiently parse CSV using awk?.
Assuming you have this:
BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109,07",DF,CCCCCCCCCCC
Try this:
awk -F',' '{print $1,$2,$3,$4"."$5,$6,$7}' filename | awk '$1=$1' FS=" " OFS=","
Output will be:
BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109.07",DF,CCCCCCCCCCC
You simply need to know the field numbers for replacing the field separator between them.
In order to use regexp as in perl you have to activate extended regular expression with -r.
So if you want to replace all numbers and omit the " sign, then you can use this:
echo 'BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109,07",DF,CCCCCCCCCCC, .......'|sed -r 's/\"([0-9]+)\,([0-9]+)\"/\1\.\2/g'
If you want to replace first occurrence only you can use that:
echo 'BBBBBBB.2018_08,XXXXXXXXXXXXX,01/01/2014,"109,07",DF,CCCCCCCCCCC, .......'|sed -r 's/\"([0-9]+)\,([0-9]+)\"/\1\.\2/1'
https://www.gnu.org/software/sed/manual/sed.txt

Using command line to remove text?

I have a huge file that contains lines that follow this format:
New-England-Center-For-Children-L0000392290
Southboro-Housing-Authority-L0000392464
Crew-Star-Inc-L0000391998
Saxony-Ii-Barber-Shop-L0000392491
Test-L0000392334
What I'm trying to do is narrow it down to just this:
New-England-Center-For-Children
Southboro-Housing-Authority
Crew-Star-Inc
Test
Can anyone help with this?
Using GNU awk:
awk -F\- 'NF--' OFS=\- file
New-England-Center-For-Children
Southboro-Housing-Authority
Crew-Star-Inc
Saxony-Ii-Barber-Shop
Test
Set the input and output field separator to -.
NF contains number of fields. Reduce it by 1 to remove the last field.
Using sed:
sed 's/\(.*\)-.*/\1/' file
New-England-Center-For-Children
Southboro-Housing-Authority
Crew-Star-Inc
Saxony-Ii-Barber-Shop
Test
Simple greedy regex to match up to the last hyphen.
In replacement use the captured group and discard the rest.
Version 1 of the Question
The first version of the input was in the form of HTML and parts had to be removed both before and after the desired text:
$ sed -r 's|.*[A-Z]/([a-zA-Z-]+)-L0.*|\1|' input
Special-Restaurant
Eliot-Cleaning
Kennedy-Plumbing
Version 2 of the Question
In the revised question, it is only necessary to remove the text that starts with -L00:
$ sed 's|-L00.*||' input2
New-England-Center-For-Children
Southboro-Housing-Authority
Crew-Star-Inc
Saxony-Ii-Barber-Shop
Test
Both of these commands use a single "substitute" command. The command has the form s|old|new|.
The perl code for this would be: perl -nle'print $1 if(m{-.*?/(.*?-.*?)-})
We can break the Regex down to matching the following:
- for that's between the city and state
.*? match the smallest set of character(s) that makes the Regex work, i.e. the State
/ matches the slash between the State and the data you want
( starts the capture of the data you are interested in
.*?-.*? will match the data you care about
) will close out the capture
- will match the dash before the L####### to give the regex something to match after your data. This will prevent the minimal Regex from matching 0 characters.
Then the print statement will print out what was captured (your data).
awk likes these things:
$ awk -F[/-] -v OFS="-" '{print $(NF-3), $(NF-2)}' file
Special-Restaurant
Eliot-Cleaning
Kennedy-Plumbing
This sets / and - as possible field separators. Based on them, it prints the last_field-3 and last_field-2 separated by the delimiter -. Note that $NF stands for last parameter, hence $(NF-1) is the penultimate, etc.
This sed is also helpful:
$ sed -r 's#.*/(\w*-\w*)-\w*\.\w*</loc>$#\1#' file
Special-Restaurant
Eliot-Cleaning
Kennedy-Plumbing
It selects the block word-word after a slash / and followed with word.word</loc> + end_of_line. Then, it prints back this block.
Update
Based on your new input, this can make it:
$ sed -r 's/(.*)-L\w*$/\1/' file
New-England-Center-For-Children
Southboro-Housing-Authority
Crew-Star-Inc
Saxony-Ii-Barber-Shop
Test
It selects everything up to the block -L + something + end of line, and prints it back.
You can use also another trick:
rev file | cut -d- -f2- | rev
As what you want is every slice of - separated fields, let's get all of them but last one. How? By reversing the line, getting all of them from the 2nd one and then reversing back.
Here's how I'd do it with Perl:
perl -nle 'm{example[.]com/bp/(.*?)/(.*?)-L\d+[.]htm} && print $2' filename
Note: the original question was matching input lines like this:
<loc>http://www.example.com/bp/Lowell-MA/Special-Restaurant-L0000423916.htm</loc>
<loc>http://www.example.com/bp/Houston-TX/Eliot-Cleaning-L0000422797.htm</loc>
<loc>http://www.example.com/bp/New-Orleans-LA/Kennedy-Plumbing-L0000423121.htm</loc>
The -n option tells Perl to loop over every line of the file (but not print them out).
The -l option adds a newline onto the end of every print
The -e 'perl-code' option executes perl-code for each line of input
The pattern:
/regex/ && print
Will only print if the regex matches. If the regex contains capture parentheses you can refer to the first captured section as $1, the second as $2 etc.
If your regex contains slashes, it may be cleaner to use a different regex delimiter ('m' stands for 'match'):
m{regex} && print
If you have a modern Perl, you can use -E to enable modern feature and use say instead of print to print with a newline appended:
perl -nE 'm{example[.]com/bp/(.*?)/(.*?)-L\d+[.]htm} && say $2' filename
This is very concise in Perl
perl -i.bak -lpe's/-[^-]+$//' myfile
Note that this will modify the input file in-place but will keep a backup of the original data in called myfile.bak

How to use sed-awk-gawk to display a matched string

I've got a file called 'res' that's 29374 characters of http data in a one-line string. Inside it, there are several http links, but I only want to be display those that end in '/idNNNNNNNNN' where N is a digit. In fact I'm only interested in the string 'idNNNNNNNNN'.
I've tried with:
cat res | sed -n '0,/.*\(id[0-9]*\).*/s//\1/p'
but I get the whole file.
Do you know a way to do it?
perl -n -E 'say $1 while m!/id(\d{9})!g' input-file
should work. That assumes exactly 9 digits; that's the {9} in the above. You can match 8 or 9 ({8,9}), 8 or more ({8,}), up to 9 ({0,9}), etc.
Example of this working:
$ echo -n 'junk jumk http://foo/id231313 junk lalala http://bar/id23123 asda' | perl -n -E 'say $1 while m!id(\d{0,9})!g'
231313
23123
That's with the 0 to 9 variant, of course.
If you're stuck with a pre-5.10 perl, use -e instead of -E and print "$1\n" instead of say $1.
How it works
First is the two command-line arguments to Perl. -n tells Perl to read input from standard input or files given on the command line, line by line, setting $_ to each line. $_ is perl's default target for a lot of things, including regular expression matches. -E merely tells Perl that the next argument is a Perl one-liner, using the new language features (vs. -e which does not use the 5.10 extensions).
So, looking at the one liner: say means to print out some value, followed by a newline. $1 is the first regular expression capture (captures are made by parentheses in regular expressions). while is a looping construct, which you're probably familiar with. m is the match operator, the ! after it is the regular expression delimiter (normally, you see / here, but since the pattern contains / it's easier to use something else, so you don't have to escape the / as \/). /id(\d{9}) is the regular expression to match. Keep in mind that the delimiter is !, so the / is not special, it just matches a literal /. The parentheses form a capture group, so $1 will be the number. The ! is the delimiter, followed by g which means to match as many times as possible (as opposed to once). This is what makes it pick up all the URLs in the line, not just the first. As long as there is a match, the m operator will return a true value, so the loop will continue (and run that say $1, printing out the match).
Two-sed solution
I think this is one way to do this with only sed. Much more complicated!
echo 'junk jumk http://foo/id231313 junk lalala http://bar/id23123 asda' | \
sed 's!http://!\nhttp://!g' | \
sed 's!^.*/id\([0-9]*\).*$!\1!'
cat res | perl -ne 'chomp; print "$1\n" if m/\/(id\d*)/'
The trouble is that sed and grep and awk work on lines, and you've only got one line. So, you probably need to split things up so you have more than one line -- then you can make the normal tools work.
tr ':' '\012' < res |
sed -n 's%.*/\(id[0-9][0-9]*\).*%\1%p'
This takes advantage of URLs containing colons and maps colons to newlines with tr, then uses sed to pick up anything up to a slash, followed by id and one or more digits, followed by anything, and prints out the id and digit string (only). Since these only occur in URLs, they will only appear one per line and relatively near the start of the line too.
Here's a solution using only one invocation of sed:
sed -n 's| |\n|g;/^http/{s|http://[^/]*/id\([0-9]*\)|\1|;P};D' inputfile
Explanation:
s| |\n|g; - Divide and conquer
/^http/{ - If pattern space begins with "http"
s|http://[^/]*/id\([0-9]*\)|\1|; - capture the id
P - Print the string preceding the first newline
}; - end if
D - Delete the string preceding the first newline regardless of whether it contains "http"
Edit:
This version uses the same technique but is more selective.
sed -n 's|http://|\n&|g;/^\n*http/{s|\n*http://[^/]*/id\([0-9]*\)|\1\n|;P};D' inputfile