Sorry if it is a duplicate, but I really couldn't find an answer.
How could I solve this one: I have a base .txt file (base.txt), and I want to perform the command "cat base.txt | fgrep string_to_find.txt", where string_to_find.txt contains the string I want to use with fgrep. I have a lot of string_to_find.txt files, so I can't do it one by one manually, I have to automate the task, most probably with a bash script.
Thanks!
Since the .txt file contains exactly the string I want to search, just solved with cat base.txt | fgrep "$(cat string_to_find.txt)".
Related
I am a beginner of bash script. I just started to write a script where it checks the contents of b.txt can all be found in a.txt. (line by line preferably). My code is as following:
grep -Ffw b.txt a.txt
As you can see, I want to do fixed string instead of REGEX, I want to check everything from the b.txt file, because there are some strings inside the b.txt and I want to check if all of them exist in a.txt. And I also want to match the whole word only of course. So these are the requirements, however when I run this command it returns me an error says: grep: w: No such file or directory
I am thinking that maybe there are some limitations of the flags in bash? Sorry I am not really familiar with the language, didn't read much about the MAN page etc. If anyone could help me to solve the puzzle it would be appreciated :) In addition, i think if possible I would like to add a -q to surpress the output when there is a match also, right now I didn't add it in the example since it couldn't make it through with 3 flags even. So can anyone give me some hints here? Thanks in advance!
Hereby some explanation from the manpage:
OPTIONS
Generic Program Information
...
-F, --fixed-strings
Interpret PATTERNS as fixed strings, ...
-f FILE, --file=FILE
Obtain patterns from FILE, ...
-w, --word-regexp
Select only those lines ...
As you can see, the options -F and -w are indicated ending immediately (hence the comma in -F, and -w,), but the -f switch is followed by FILE, with means they belong together.
I you want to preserve the order Ffw, that's possible, but then you need to do something like:
grep -Ff b.txt -w a.txt
As mentioned by #kvantour, the solution is simply placing the -f before the b.txt file. grep -Fwf b.txt a.txt
Should have thought it when it says 'no such file or directory' as it was a clear indication that flags after the -f were treated as the path already.
In the midst of building a site checker I have ran unto a problem, the client needs to check all of their pages for certain strings if they are included in the code and then list the files that do not have the code yet.
Tried with multiple grep commands with no success. The -v supposedly exports the inverted match of the results, but that does not happen. Currently I am missing the part of the code telling grep to only search in specific files (example files names code.php) in all sub folders.
With the current code it searches all the files even unnecessary ones.
grep -vrn '.' -e "SRING" > list.txt
I'd like to export a list of files (preferably that it only checks files in all sub folders with the same name) that do not posses the sting that I am looking for.
grep -c STRING files will give you a count of lines with STRING for each file.
You can optomize it somewhat with -m1 to stop after the first match.
You can pipe that to sed to grab the files with zero matches:
grep -cm1 STRING files | sed -n '/:0$/s/:0//p'
That gets you one file per line.
You can pipe that to xargs to merge it into a one-line list.
If your STRING is just that and not a regex, you could use the -F flag with grep to specify it's a fixed string, and that will also speed things up. So maybe...
grep -Fcm1 STRING files | sed -n '/:0$/s/:0//p' > list.txt
...in that case
I'm trying to localize a 'C' project but I have no idea how to extract Strings by xgettext . And project has so many C files so extracting one by one is not feasible. S is it possible to extract strings from all files once. or there is any other way?
Thanks in advance
You can pipe all of your *.c files to the xgettext program using xargs assuming you're on Linux/Mac, e.g:
~$ find MyFolder -name "*.c \
| xargs xgettext --keyword=_ --language=C --output=messages.pot -
Be sure to pass - as the last parameter so it reads all files from stdin. Also you'll want to replace my simple keyword=_ example with the correct C function names.
From similar question in php, it is easy to know:
find . -iname "*.c" | xargs xgettext
This question already has answers here:
Match two strings in one line with grep
(23 answers)
Closed 3 years ago.
How do I grep for lines that contain two input words on the line? I'm looking for lines that contain both words, how do I do that? I tried pipe like this:
grep -c "word1" | grep -r "word2" logs
It just stucks after the first pipe command.
Why?
Why do you pass -c? That will just show the number of matches. Similarly, there is no reason to use -r. I suggest you read man grep.
To grep for 2 words existing on the same line, simply do:
grep "word1" FILE | grep "word2"
grep "word1" FILE will print all lines that have word1 in them from FILE, and then grep "word2" will print the lines that have word2 in them. Hence, if you combine these using a pipe, it will show lines containing both word1 and word2.
If you just want a count of how many lines had the 2 words on the same line, do:
grep "word1" FILE | grep -c "word2"
Also, to address your question why does it get stuck : in grep -c "word1", you did not specify a file. Therefore, grep expects input from stdin, which is why it seems to hang. You can press Ctrl+D to send an EOF (end-of-file) so that it quits.
Prescription
One simple rewrite of the command in the question is:
grep "word1" logs | grep "word2"
The first grep finds lines with 'word1' from the file 'logs' and then feeds those into the second grep which looks for lines containing 'word2'.
However, it isn't necessary to use two commands like that. You could use extended grep (grep -E or egrep):
grep -E 'word1.*word2|word2.*word1' logs
If you know that 'word1' will precede 'word2' on the line, you don't even need the alternatives and regular grep would do:
grep 'word1.*word2' logs
The 'one command' variants have the advantage that there is only one process running, and so the lines containing 'word1' do not have to be passed via a pipe to the second process. How much this matters depends on how big the data file is and how many lines match 'word1'. If the file is small, performance isn't likely to be an issue and running two commands is fine. If the file is big but only a few lines contain 'word1', there isn't going to be much data passed on the pipe and using two command is fine. However, if the file is huge and 'word1' occurs frequently, then you may be passing significant data down the pipe where a single command avoids that overhead. Against that, the regex is more complex; you might need to benchmark it to find out what's best — but only if performance really matters. If you run two commands, you should aim to select the less frequently occurring word in the first grep to minimize the amount of data processed by the second.
Diagnosis
The initial script is:
grep -c "word1" | grep -r "word2" logs
This is an odd command sequence. The first grep is going to count the number of occurrences of 'word1' on its standard input, and print that number on its standard output. Until you indicate EOF (e.g. by typing Control-D), it will sit there, waiting for you to type something. The second grep does a recursive search for 'word2' in the files underneath directory logs (or, if it is a file, in the file logs). Or, in my case, it will fail since there's neither a file nor a directory called logs where I'm running the pipeline. Note that the second grep doesn't read its standard input at all, so the pipe is superfluous.
With Bash, the parent shell waits until all the processes in the pipeline have exited, so it sits around waiting for the grep -c to finish, which it won't do until you indicate EOF. Hence, your code seems to get stuck. With Heirloom Shell, the second grep completes and exits, and the shell prompts again. Now you have two processes running, the first grep and the shell, and they are both trying to read from the keyboard, and it is not determinate which one gets any given line of input (or any given EOF indication).
Note that even if you typed data as input to the first grep, you would only get any lines that contain 'word2' shown on the output.
Footnote:
At one time, the answer used:
grep -E 'word1.*word2|word2.*word1' "$#"
grep 'word1.*word2' "$#"
This triggered the comments below.
you could use awk. like this...
cat <yourFile> | awk '/word1/ && /word2/'
Order is not important. So if you have a file and...
a file named , file1 contains:
word1 is in this file as well as word2
word2 is in this file as well as word1
word4 is in this file as well as word1
word5 is in this file as well as word2
then,
/tmp$ cat file1| awk '/word1/ && /word2/'
will result in,
word1 is in this file as well as word2
word2 is in this file as well as word1
yes, awk is slower.
The main issue is that you haven't supplied the first grep with any input. You will need to reorder your command something like
grep "word1" logs | grep "word2"
If you want to count the occurences, then put a '-c' on the second grep.
git grep
Here is the syntax using git grep combining multiple patterns using Boolean expressions:
git grep -e pattern1 --and -e pattern2 --and -e pattern3
The above command will print lines matching all the patterns at once.
If the files aren't under version control, add --no-index param.
Search files in the current directory that is not managed by Git.
Check man git-grep for help.
See also:
How to use grep to match string1 AND string2?
Check if all of multiple strings or regexes exist in a file.
How to run grep with multiple AND patterns?
For multiple patterns stored in the file, see: Match all patterns from file at once.
You cat try with below command
cat log|grep -e word1 -e word2
Use grep:
grep -wE "string1|String2|...." file_name
Or you can use:
echo string | grep -wE "string1|String2|...."
I used the following syntax in order to find IP address under /etc
(answered by Dennis Williamson in superuser site)
but I get the message "grep: line too long".
Someone have idea how to ignore this message and why I get this?
grep -Er '\<([0-9]{1,3}\.){3}[0-9]{1,3}\>' /etc/
grep: line too long
The find/xargs solution didn't work for me, but resulted in the same error.
I solved this problem by using the -I grep option (ignore binary files). In my case there must have been a binary file in the list of files to search that had no linebreaks, so grep tries to read in a gigantic line that is too big. That's my guess at what this error means.
I got the idea from: http://web.archiveorange.com/archive/v/am8x7wI0r0243prrmYd4
This might not work for you of course if there's a text file with a line that is too long.
Use find to build a list of files to grep,
find /etc -type f -print0 | xargs -r0 grep -E '\<([0-9]{1,3}\.){3}[0-9]{1,3}\>'
In general find is a more flexible way of traversing the filesystem and building lists of files for other programs.
Perhaps your grep has a bug and scans by accident a binary file with too long lines (i.e. too much characters for grep to handle between two newlines). See this red hat page for more details (bug page).