grep with negative pattern - linux

I am looking for a way to grep a file for a specific pattern with negative pattern in it.
I have a log file witch reports units version and I want to see if there is a unit witch report version other then 26.
The closest I could get is :
cat my.log | grep -i -e "version=0x[^2][^6]"
The above return a line contain "version=0x13" but not return a line contain "version=0x23"
Is there a way to tell grep to do so ?
Thanks.

Interpret the pattern as a perl regular expression using the -P switch:
grep -iP 'version=0x(?!26)\d\d' my.log

grep -i "version=0x[0-9]\\+" my.log | grep -iv "version=0x26"

Related

How to grep while excluding some words?

I wanted to grep the word "force" but most of the output listed is from the command -force.
When I did grep -v "-force" filename , it says grep : orce most probably because of the -f command.
I just want to find a force signal from files using grep. How?
use grep -v -- "-force" - the double - signals that there are no more options being expected.
If you want to grep specific word from file then we can use cat command
# cat filename.txt | grep force
For other basic Commands
this line maybe simpler:
grep '[^-]force' tmp
it says: grep "force", but only if it does not has a prefix - by using [^]. See some simple regular expression examples here.
Use [-] to remove the special significance. Check this out:
> cat rand_file.txt
1. list items of random text
2. -force
3. look similar as the first batch
4. force
5. some random text
> grep -v "-force" rand_file.txt
grep: orce: No such file or directory
> grep -v "[-]force" rand_file.txt | grep force
4. force
>

Why grep gives error for search pattern i.e. grep: <some pattern>: No such file or directory

I want to print the selected lines using grep pattern matching. I am using following command -
cat MyTest.txt | grep -v -E B1 "EEB|SET|PET"
grep: EEB|SET|PET: No such file or directory
I am always getting above grep error.
I want to print the line which matches pattern or patterns I have mentioned i.e EEB or SET or PET or All of these and
A single line prior to matching line. hence option -B1
You can use this command without useless cat:
grep -v -E -B1 "EEB|SET|PET" MyTest.txt
Note - before B1.
However from your description it appears you may not need -v (inverse results) and want this:
grep -E -B1 "EEB|SET|PET" MyTest.txt
Grep has the following syntax:
grep options pattern input_file_names
where options are optional, but not pattern. So B1 without "-" is used as pattern and "EEB|SET|PET" as file_names.
You should change "B1" to "-B1".
As recommendation
cat MyTest.txt | grep -v -E -B1 "EEB|SET|PET"
to
grep -v -E -B1 "EEB|SET|PET" MyTest.txt

Grep filter not stop at first match

I am trying to use
grep -o "javascript:add2BasketProd.*?jpg"
to extract string from
javascript:add2BasketProd('xKonfGFJsakj', 'Tattoo-Bubble-Gum-7cm-Bubble-Gum.jpg')Funny-Glasses-and-Teeth-Toy-Candy-TC-747-.jpg
but it would give no output. So I changed the code to the following but the output I get is entire string and not until the first match of jpg.
grep -o "javascript:add2BasketProd.*\?jpg"
My expected output is:
javascript:add2BasketProd('xKonfGFJsakj', 'Tattoo-Bubble-Gum-7cm-Bubble-Gum.jpg
Can anyone suggest a solution?
grep uses POSIX style regular expression which are always greedy. If your grep supports the -P flag, you can use it to enable perl style regex which do support non-greedy matches:
grep -oP "javascript:add2BasketProd.*?jpg"
The GNU grep, which is used on linux, supports -P. The Mac OSX grep does not.
You can use egrep for advanced regex capabilities:
s='javascript:add2BasketProd('xKonfGFJsakj', 'Tattoo-Bubble-Gum-7cm-Bubble-Gum.jpg')Funny-Glasses-and-Teeth-Toy-Candy-TC-747-.jpg'
egrep -o "javascript:add2BasketProd.*?jpg" <<< "$s"
javascript:add2BasketProd(xKonfGFJsakj, Tattoo-Bubble-Gum-7cm-Bubble-Gum.jpg

Grep Search all files in directory for string1 AND string2

How can I make use of grep in cygwin to find all files that contain BOTH words.
This is what I use to search all files in a directory recursively for one word:
grep -r "db-connect.php" .
How can I extend the above to look for files that contain both "db-connect.php" AND "version".
I tried this: grep -r "db-connect.php\|version" . but this is an OR i.e. it gets file that contain one or the other.
Thanks all for any help
grep -r db-connect.php . | grep version
If you want to grep for several strings in a file which have different lines, use the following command:
grep -rl expr1 | xargs grep -l expr2 | xargs grep -l expr3
This will give you a list of files that contain expr1, expr2, and expr3.
Note that if any of the file names in the directory contains spaces, these files will produce errors. This can be fixed by adding -0 I think to grep and xargs.
grep "db-connect.php" * | cut -d: -f1 | xargs grep "version"
I didn't try it in recursive mode but it should be the same.
To and together multiple searches, use multiple lookahead assertions, one per thing looked for apart from the last one:
instead of writing
grep -P A * | grep B
you write
grep -P '(?=.*A)B' *
grep -Pr '(?=.*db-connect\.php)version' .
Don’t write
grep -P 'A.*B|B.*A' *
because that fails on overlaps, whereas the (?=…)(?=…) technique does not.
You can also add in NOT operators as well. To search for lines that don’t match X, you normally of course use -v on the command line. But you can’t do that if it is part of a larger pattern. When it is, you add (?=(?!X).)*$) to the pattern to exclude anything with X in it.
So imagine you want to match lines with all three of A, B, and then either of C or D, but which don’t have X or Y in them. All you need is this:
grep -P '(?=^.*A)(?=^.*B)(?=^(?:(?!X).)*$)(?=^(?:(?!Y).)*$)C|D' *
In some shells and in some settings. you’ll have to escape the ! if it’s your history-substitution character.
There, isn’t that pretty cool?
In my cygwin the given answers didn't work, but the following did:
grep -l firststring `grep -r -l secondstring . `
Do you mean "string1" and "string2" on the same line?
grep 'string1.*string2'
On the same line but in indeterminate order?
grep '(string1.*string2)|(string2.*string1)'
Or both strings must appear in the file anywhere?
grep -e string1 -e string2
The uses PCRE (Perl-Compatible Regular Expressions) with multiline matching and returns the filenames of files that contain both strings (AND rather than OR).
grep -Plr '(?m)db-connect\.php(.*\n)*version|version(.*\n)*db-connect\.php' .
Why to stick to only grep:
perl -lne 'print if(/db-connect.php/&/version/)' *

Pipe output to use as the search specification for grep on Linux

How do I pipe the output of grep as the search pattern for another grep?
As an example:
grep <Search_term> <file1> | xargs grep <file2>
I want the output of the first grep as the search term for the second grep. The above command is treating the output of the first grep as the file name for the second grep. I tried using the -e option for the second grep, but it does not work either.
You need to use xargs's -i switch:
grep ... | xargs -ifoo grep foo file_in_which_to_search
This takes the option after -i (foo in this case) and replaces every occurrence of it in the command with the output of the first grep.
This is the same as:
grep `grep ...` file_in_which_to_search
Try
grep ... | fgrep -f - file1 file2 ...
If using Bash then you can use backticks:
> grep -e "`grep ... ...`" files
the -e flag and the double quotes are there to ensure that any output from the initial grep that starts with a hyphen isn't then interpreted as an option to the second grep.
Note that the double quoting trick (which also ensures that the output from grep is treated as a single parameter) only works with Bash. It doesn't appear to work with (t)csh.
Note also that backticks are the standard way to get the output from one program into the parameter list of another. Not all programs have a convenient way to read parameters from stdin the way that (f)grep does.
I wanted to search for text in files (using grep) that had a certain pattern in their file names (found using find) in the current directory. I used the following command:
grep -i "pattern1" $(find . -name "pattern2")
Here pattern2 is the pattern in the file names and pattern1 is the pattern searched for
within files matching pattern2.
edit: Not strictly piping but still related and quite useful...
This is what I use to search for a file from a listing:
ls -la | grep 'file-in-which-to-search'
Okay breaking the rules as this isn't an answer, just a note that I can't get any of these solutions to work.
% fgrep -f test file
works fine.
% cat test | fgrep -f - file
fgrep: -: No such file or directory
fails.
% cat test | xargs -ifoo grep foo file
xargs: illegal option -- i
usage: xargs [-0opt] [-E eofstr] [-I replstr [-R replacements]] [-J replstr]
[-L number] [-n number [-x]] [-P maxprocs] [-s size]
[utility [argument ...]]
fails. Note that a capital I is necessary. If i use that all is good.
% grep "`cat test`" file
kinda works in that it returns a line for the terms that match but it also returns a line grep: line 3 in test: No such file or directory for each file that doesn't find a match.
Am I missing something or is this just differences in my Darwin distribution or bash shell?
I tried this way , and it works great.
[opuser#vjmachine abc]$ cat a
not problem
all
problem
first
not to get
read problem
read not problem
[opuser#vjmachine abc]$ cat b
not problem xxy
problem abcd
read problem werwer
read not problem 98989
123 not problem 345
345 problem tyu
[opuser#vjmachine abc]$ grep -e "`grep problem a`" b --col
not problem xxy
problem abcd
read problem werwer
read not problem 98989
123 not problem 345
345 problem tyu
[opuser#vjmachine abc]$
You should grep in such a way, to extract filenames only, see the parameter -l (the lowercase L):
grep -l someSearch * | xargs grep otherSearch
Because on the simple grep, the output is much more info than file names only. For instance when you do
grep someSearch *
You will pipe to xargs info like this
filename1: blablabla someSearch blablabla something else
filename2: bla someSearch bla otherSearch
...
Piping any of above line makes nonsense to pass to xargs.
But when you do grep -l someSearch *, your output will look like this:
filename1
filename2
Such an output can be passed now to xargs
I have found the following command to work using $() with my first command inside the parenthesis to have the shell execute it first.
grep $(dig +short) file
I use this to look through files for an IP address when I am given a host name.

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