Bash - Retrieving Strings of Text in Files with Regular Expressions - regex

I'm sorry if the title was poorly worded. Here's the idea. Let's say that I have many files and I wish to find all occurrences of a particular expression such as:
tag:"some text I wish to retrieve"
Note that the entire line above would appear in the files. I wish to copy only what is in the quotation marks after the word 'tag'.
I'm not an expert at bash by any means, but I could easily use grep to retrieve the entire line that contains the regular expression. Easy. However, I only want part of that line. The text in quotation marks varies in length. Ultimately I want to amalgamate all occurrences into one file.
For instance, I would want to take FILE 1 and FILE 2 and end up with FILE 3:
FILE 1:
whatever:"text I don't want"
something:"More text I don't want" tag:"some text I wish to retrieve"
FILE 2:
whatever:"don't want" tag:"more text I wish to retrieve" something:"nope"
FILE 3:
some text I wish to retrieve
more text I wish to retrieve
Can this be accomplished using bash? I could do it in C with a bit of effort, but I'd rather not if I don't have to.
EDIT:
"-o" is used to show only the part of the line that matches the expression. I don't know how I missed that in the man page.

You can use grep to perform this task.
grep -hrPo 'tag:"\K[^"]*' * > result

Here is a gnu awk (gnu due to multiple characters in RS) version:
awk -v RS="tag:" -F\" '{$1=$1} FNR>1 {print $2}' FILE*
some text I wish to retrieve
more text I wish to retrieve
This should work with all version of awk:
awk -F\" '{for (i=1;i<=NF;i++) if ($i~" tag:") print $(i+1)}' FILE*
some text I wish to retrieve
more text I wish to retrieve

Related

Insert newline before/after match for TSV

I'm going grey trying to figure out how to accomplish some regex matching to insert new lines. Example input/output below...
Example TSV Data:
Name Monitoring Tags
i-RBwPyvq8wPbUhn495 enabled "some:tags:with:colons=some:value:with:colons-and-dashes/and/slashes/yay606-values-001 some:other:tag:with-colons-and-hypens=MACHINE NAME Name=NAMETAG backup=true"
i-sMEwh2MXj3q47yWWP enabled "description=RANDOM BUSINESS INT01 backup=true Name=SOMENAME"
Desired Output:
Name Monitoring Tags
i-RBwPyvq8wPbUhn495 enabled "some:tags:with:colons=some:value:with:colons-and-dashes/and/slashes/yay606-values-001
some:other:tag:with-colons-and-hyphens=MACHINE NAME
Name=NAMETAG
backup=true"
i-sMEwh2MXj3q47yWWP enabled "description=RANDOM BUSINESS INT01
backup=true
Name=SOMENAME"
I can guarantee each key=value within those quotes are separated by hard/literal tabs, although it may not appear that way with how the StackOverflow code block is displayed in HTML they did carry over into the code block editor, the data under the column Tags is in quotes so that even though they are tab separated they stay within the Tags column. For whatever reason I'm not able to successfully get the desired results.
In my measly attempts, I've been basically capturing everything between the "" as if tabs aren't separated in my regex searches because of my use of wildcards [TAB].*=.*[TAB] is obviously not working because then I'm losing everything in between the first/last occurrence for each line. I've attempted storing them in capture groups without any success.
I'm looking for a unix toolset solution (sed, awk, perl and the like). Any/All help is appreciated!
This will work using any awk in any shell on any UNIX box:
$ awk 'match($0,/".*"/){str=substr($0,RSTART,RLENGTH); gsub(/\t/,"\n",str); $0=substr($0,1,RSTART-1) str substr($0,RSTART+RLENGTH)} 1' file
Name Monitoring Tags
i-RBwPyvq8wPbUhn495 enabled "some:tags:with:colons=some:value:with:colons-and-dashes/and/slashes/yay606-values-001
some:other:tag:with-colons-and-hypens=MACHINE NAME
Name=NAMETAG
backup=true"
i-sMEwh2MXj3q47yWWP enabled "description=RANDOM BUSINESS INT01
backup=true
Name=SOMENAME"
It just extracts a string between "s from the current record, replaces all tabs with newlines within that string, then puts the record back together before it's printed.
You can try this sed (GNU sed) 4.4
sed -E ':A;s/(".*)\t(.*")/\1\n\2/;tA' TSV_Data_File
With OSX sed, you can try this one.
I think the \t is ok.
sed -E '
:A
s/(".*)\t(.*")/\1\
\2/
tA
' TSV_Data_File
brief explain :
Catch the text inside "
Substitute the last \t by \n
If a substitution occur jump to A else continue
With awk :
awk -v RS='"' 'NR%2==0{gsub("\t","\n")}1' ORS='"' TSV_Data_File
This is basically ctac_'s awk answer converted to perl:
perl -pe'1 while s/(".*)\t(.*")/$1\n$2/s' file.tsv
Where the \t might be replaced by \t\s* if you want just one newline out of each tab-and-then-some.
This might work for you (GNU sed):
sed 's/\S\+=\S\+/\n&/2g' file
Insert a newline in before the second or more non-empty strings containing an =.

Regex command line change format of each line

I have a file that contains lines in a format similar to this...
/data/file.geojson?10,20,30,40
/data/file.geojson?bbox=-5.20751953125,49.05227025601607,3.0322265625,56.46249048388979
/data/file.geojson?bbox=-21.46728515625,45.99696161820381,19.2919921875,58.88194208135912
/data/file.geojson?bbox=-2.8482055664062496,54.38935426009769,-0.300750732421875,55.158473983815306
/data/file.geojson?bbox=-21.46728515625,45.99696161820381,19.2919921875,58.88194208135912
/data/file.geojson?bbox=-21.46728515625,45.99696161820381,19.2919921875,58.88194208135912
I've tried a combination of grep, sed, gawk, and |(pipes) to try and pattern match and then change the format to be more like this...
[10,40],[30,40],[30,20][10,20],
[-5.20751953125,56.46249048388979],[3.0322265625,56.46249048388979].....
Hopefully you get the idea from the first line so I don't have to type out all the examples manually!
I've got the hang of regex to match the co-ordinates. In fact the input file is the result of extracting from apache access logs. It might be easier to read/understand answers if they just match positive integer numbers, I will then be able to slot in a more complicated pattern to match the right range.
To be able to arrange the results like you which it is important to be able to access the last for values per line.
No pattern matching is required if you use awk. You can split the input strings by a set of delimiters and reassemble the resulting fields. 40 can be accessed as $(NF), 30 as $(NF-1) and so on.
awk -F'[?,=]' '
{printf "[%s,%s],[%s,%s],[%s,%s],[%s,%s]\n",
$(NF-3),$(NF),$(NF-1),$(NF),
$(NF-1),$(NF-2),$(NF-3),$(NF-2)
}' file
I'm using ?, , or = as the field delimiters. This makes it simple to access the columns of interest.
Output:
[10,40],[30,40],[30,20],[10,20]
[-5.20751953125,56.46249048388979],[3.0322265625,56.46249048388979],[3.0322265625,49.05227025601607],[-5.20751953125,49.05227025601607]
[-21.46728515625,58.88194208135912],[19.2919921875,58.88194208135912],[19.2919921875,45.99696161820381],[-21.46728515625,45.99696161820381]
[-2.8482055664062496,55.158473983815306],[-0.300750732421875,55.158473983815306],[-0.300750732421875,54.38935426009769],[-2.8482055664062496,54.38935426009769]
[-21.46728515625,58.88194208135912],[19.2919921875,58.88194208135912],[19.2919921875,45.99696161820381],[-21.46728515625,45.99696161820381]
[-21.46728515625,58.88194208135912],[19.2919921875,58.88194208135912],[19.2919921875,45.99696161820381],[-21.46728515625,45.99696161820381]
Btw, also sed can be used here:
sed -r 's/.*[?=]([^,]+),([^,]+),([^,]+),(.*)/[\1,\4],[\3,\4],[\3,\2],[\1,\2]/' file
The command is capturing the numbers at the end each in a separate capturing group and re-assembles them in the replacement part.
Not all versions of sed support the + quantifier. The most compatible version would look like this :)
sed 's/.*[?=]\([^,]\{1,\}\),\([^,]\{1,\}+\),\([^,]\{1,\}\),\(.*\)/[\1,\4],[\3,\4],[\3,\2],[\1,\2]/' file
sed strips off items prior to numbers, then awk splits on comma and outputs in different order. Assuming data is in a file called "td.txt"
sed 's/^[^0-9-]*//' td.txt|awk -F, '{print "["$1","$4"],["$3","$4"],["$3","$2"],["$1","$2"],"}'
This might work for you (GNU sed):
sed -r 's/^.*\?[^-0-9]*([^,]*),([^,]*),([^,]*),([^,]*)/[\1,\4],[\3,\4],[\3,\2],[\1,\2]/' file
Or with more toothpicks:
sed 's/^.*\?[^-0-9]*\([^,]*\),\([^,]*\),\([^,]*\),\([^,]*\)/[\1,\4],[\3,\4],[\3,\2],[\1,\2]/' file
You can use the following to match:
(\/data\/file\.geojson\?(?:bbox=)?)([0-9.-]+),([0-9.-]+),([0-9.-]+),([0-9.-]+)
And replace with the following:
$1[$2,$3],[$4,$5]
See DEMO

Grep invert on string matched, not line matched

I'll keep this explanation of why I need help to a mimimum. One of my file directories got hacked through XSS and placed a long string at the beginning of all php files. I've tried to use sed to replace the string with nothing but it won't work because the pattern to match includes many many characters that would need to be escaped.
I found out that I can use fgrep to match a fixed string saved in a pattern file, but I'd like to replace the matched string (NOT THE LINE) in each file, but grep's -v inverts the result on the line, rather than the end of the matched string.
This is the command I'm using on an example file that contains the hacked
fgrep -v -f ~/hacked-string.txt example.php
I need the output to contain the <?php that's at the end of the line (sometimes it's a <style> tag), but the -v option inverts at the end of that line, so the output doesn't contain the <?php at the beginning.
NOTE
I've tried to use the -o or --only-matching which outputs nothing instead:
fgrep -f ~/hacked-string.txt example.php --only-matching -v
Is there another option in grep that I can use to invert on the end of the matched pattern, rather than the line where the pattern was matched? Or alternatively, is there an easier option to replace the hacked string in all .php files?
Here is a small snippet of what's in hacked-string.txt (line breaks added for readability):
]55Ld]55#*<%x5c%x7825bG9}:}.}-}!#*<%x55c%x7825)
dfyfR%x5c%x7827tfs%x5c%x7c%x785c%x5c%x7825j:^<!
%x5c%x7825w%x5c%x7860%x5c%x785c^>Ew:25tww**WYsb
oepn)%x5c%x7825bss-%x5c%x7825r%x5c%x7878B%x5c%x
7825h>#]y3860msvd},;uqpuft%x5c%x7860msvd}+;!>!}
%x5c%x7827;!%x5c%x7825V%x5c%x7827{ftmfV%x5e56+9
9386c6f+9f5d816:+946:ce44#)zbssb!>!ssbnpe_GMFT%
x5c5c%x782f#00#W~!%x5c%x7825t2w)##Qtjw)#]82#-#!
#-%x5c%x7825tmw)%x5c%x78w6*%x5c%x787f_*#fubfsdX
k5%x5c%xf2!>!bssbz)%x5c%x7824]25%x5c%x7824-8257
-K)fujs%x5c%x7878X6<#o]o]Y%x5c%x78257;utpI#7>-1
-bubE{h%x5c%x7825)sutcvt)!gj!|!*bubEpqsut>j%x5c
%x7825!*72!%x5c%x7827!hmg%x5c%x78225>2q%x5c%x7
Thanks in advance!
I think what you are asking is this:
"Is it possible to use the grep utility to remove all instances of a fixed string (which might contain lots of regex metacharacters) from a file?"
In that case, the answer is "No".
What I think you wanted to ask was:
"What is the easiest way to remove all instances of a fixed string (which might contain lots of regex metacharacters) from a file?"
Here's one reasonably simple solution:
delete_string() {
awk -v s="$the_string" '{while(i=index($0,s))$0=substr($0,1,i-1)substr($0,i+length(s))}1'
}
delete_string 'some_hideous_string_with*!"_inside' < original_file > new_file
The shell syntax is slightly fragile; it will break if the string contains an apostrophe ('). However, you can read a raw string from stdin into a variable with:
$ IFS= read -r the_string
absolutely anything here
which will work with any string which doesn't contain a newline or a NUL character. Once you have the string in a variable, you can use the above function:
delete_string "$the_string" < original_file > new_file
Here's another possible one liner, using python:
delete_string() {
python -c 'import sys;[sys.stdout.write(l.replace(r"""'"$1"'""","")) for l in sys.stdin]'
}
This won't handle strings which have three consecutive quotes (""").
Is the hacked string the same in every file?
If the length of hacked string in chars was 1234 then you can use
tail -c +1235 file.php > fixed-file.php
for each infected file.
Note that tail c +1235 tells to start output at 1235th character of the input file.
With perl:
perl -i.hacked -pe "s/\Q$(<hacked-string.txt)\E//g" example.php
Notes:
The $(<file) bit is a bash shortcut to read the contents of a file.
The \Q and \E bits are from perl, they treat the stuff in between as plain characters, ignoring regex metachars.
The -i.hacked option will edit the file in-place, creating a backup "example.php.hacked"

how to parse a text file for a particular compound expressions filtering in shell scripting

I want to extract (parse) a text file which has particular word, for my requirement whatever the rows which have the words "cluster" and "week" and "8.2" it should be written to the output file.
sample text in the file
2013032308470272~800000102507~Cluster-Mode~WEEK~8.1.2~V6240
2013032308470272~800000102507~Cluster-Mode~monthly~8.1.2~V6240
2013032308470272~800000102507~Cluster-Mode~WEEK~8.2.2~V6240
2013032308470272~800000102507~Cluster-Mode~yearly~8.1.2~V6240
Desired output into another text file by above mentioned filters
2013032308470272~800000102507~Cluster-Mode~WEEK~8.2.2~V6240
I have writen a code using the awk command, however the output file contains the rows which are out of the scope of the filters.
code used to extract the text
awk '/Cluster/ && /WEEK/ && /8.2/ { print $NF > "/u/nbsvc/Data/Lookup/derived_asup_2010404_201409_2.txt" }' /u/nbsvc/Data/Lookup/cmode_asup_lookup.txt
obtained output
2013032308470272~800000102507~Cluster-Mode~WEEK~8.1.2~V6240
2013032308470272~800000102507~Cluster-Mode~WEEK~8.2.2~V6240
Note: the first line of obtained output is not needed in the desired output. How can I change my script to only get the line that I want?
To remove any ambiguity and false matches on partial fields or the wrong field, THIS is the command you need to run:
$ awk -F'~' '$3~/^Cluster/ && $4=="WEEK" && $5~/^8\.2/' file
2013032308470272~800000102507~Cluster-Mode~WEEK~8.2.2~V6240
I don't think that awk is needed at all here. Just use grep to match the line that you're interested in:
grep 'Cluster.*WEEK.*8\.2' file > output_file
The .* matches zero or more of any character and > is used to redirect the output to a new file. I have escaped the . in between "8.2" so that it is interpreted literally, rather than matching any character (although it would work either way).
there is actually little more in my requirement, it is I need to read this text file, then I need to split the line (where the cursor is) and push the values into a array and then I need to check for the values does it match with my pattern or not, if it matches then I need to write it to a out put text file, else simply ignore it, this one I did like as below..
cat /inputfolder_path/lookup_filename.txt | awk '{IGNORECASE = 1;line=$0;split(line,a, "~") ;if (a[1] ~ /201404/ && a[3]~/Cluster/ && a[4]~/WEEK/ && a[5]~/8.2/){print $0}}' > /outputfolder_path/derived_output_filename.txt
this is working exactly for my requirement..
Just thought to update this to every one, as it may help someone..
Thanks,
Siva

how to rejoin words that are split accross lines with a hyphen in a text file

OCR texts often have words that flow from one line to another with a hyphen at the end of the first line. (ie: the word has '-\n' inserted in it).
I would like rejoin all such split words in a text file (in a linux environment).
I believe this should be possible with sed or awk, but the syntax for these is dark magic to me! I knew a text editor in windows that did regex search/replace with newlines in the search expression, but am unaware of such in linux.
Make sure to back up ocr_file before running as this command will modify the contents of ocr_file:
perl -i~ -e 'BEGIN{$/=undef} ($f=<>) =~ s#-\s*\n\s*(\S+)#$1\n#mg; print $f' ocr_file
This answer is relevant, because I want the words joined together... not just a removal of the dash character.
cat file| perl -CS -pe's/-\n//'|fmt -w52
is the short answer, but uses fmt to reform paragraphs after the paragraphs were mangled by perl.
without fmt, you can do
#!/usr/bin/perl
use open qw(:std :utf8);
undef $/; $_=<>;
s/-\n(\w+\W+)\s*/$1\n/sg;
print;
also, if you're doing OCR, you can use this perl one-liner to convert unicode utf-8 dashes to ascii dash characters. note the -CS option to tell perl about utf-8.
# 0x2009 - 0x2015 em-dashes to ascii dash
perl -CS -pe 'tr/\x{2009}\x{2010}\x{2011}\x{2012\x{2013}\x{2014}\x{2015}/-/'
cat file | perl -p -e 's/-\n//'
If the file has windows line endings, you'll need to catch the cr-lf with something like:
cat file | perl -p -e 's/-\s\n//'
Hey this is my first answer post, here goes:
'-\n' I suspect are the line-feed characters. You can use sed to remove these. You could try the following as a test:
1) create a test file:
echo "hello this is a test -\n" > testfile
2) check the file has the expected contents:
cat testfile
3) test the sed command, this sends the edited text stream to standard out (ie your active console window) without overwriting anything:
sed 's/-\\n//g' testfile
(you should just see 'hello this is a test file' printed to the console without the '-\n')
If I build up the command:
a) First off you have the sed command itself:
sed
b) Secondly the expression and sed specific controls need to be in quotations:
sed 'sedcontrols+regex' (the text in quotations isn't what you'll actually enter, we'll fill this in as we go along)
c) Specify the file you are reading from:
sed 'sedcontrols+regex' testfile
d) To delete the string in question, sed needs to be told to substitute the unwanted characters with nothing (null,zero), so you use 's' to substitute, forward-slash, then the unwanted string (more on that in a sec), then forward-slash again, then nothing (what it's being substituted with), then forward-slash, and then the scale (as in do you want to apply the edit to a single line or more). In this case I will select 'g' which represents global, as in the whole text file. So now we have:
sed 's/regex//g' testfile
e) We need to add in the unwanted string but it gets confusing because if there is a slash in your string, it needs to be escaped out using a back-slash. So, the unwanted string
-\n ends up looking like -\\n
We can output the edited text stream to stdout as follows:
sed 's/-\\n//g' testfile
To save the results without overwriting anything (assuming testfile2 doesn't exist) we can redirect the output to a file:
sed 's/-\\n//g' testfile >testfile2
sed -z 's/-\n//' file_with_hyphens