Sponsored Content
Top Forums Shell Programming and Scripting Big pattern file matching within another pattern file in awk or shell Post 302960839 by RudiC on Friday 20th of November 2015 04:55:41 AM
Old 11-20-2015
Some comments on top of what Don Cragun said:
awk -F "," keys.txt '{print $1}' can't possibly work (reverse order of arguments) and is superfluous - you could simply read IFS="," key_ REST; ... < keys.txt
grep -v ",-1$" is pointless as (at least in the samples given) there's no line ending in "-1"
And, for each line in keys.txt times each matching line in file1.txt, you run 10 processes to extract a few fields - no surprise that is slow.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Pattern matching for file

Hi All, I'm new to perl, My requirement is to check if particular file exists. e.g. filename.txt, filename1.txt, filename2.txt etc I tried the below code:- my $var1 = "filename.txt" if ( -e ($var1 = ~ /file\w/)) { print "File found \n"; } else { print "File not found \n"; } ... (0 Replies)
Discussion started by: doitnow
0 Replies

2. Programming

File Pattern Matching C++

Hi, I have large files with fixed length fields or fields seperated by delimeter. I would like to do validation on some or all fields to check for numeric or date or characters etc.. I would like to write this in C++. Please let me know if any one have any ideas on this. Thanks for all... (2 Replies)
Discussion started by: rameshmelam
2 Replies

3. UNIX for Dummies Questions & Answers

PERL pattern matching in a file

Hi Gurus, I have a file like below.. I have to match each with predefined pattern. If matches then have to write the entire record to a separate file. If not make the value as NULL and write the entire record into another file. | is the delimiter ravi123|2344|M R123Vi|2345|F... (8 Replies)
Discussion started by: pvksandeep
8 Replies

4. Shell Programming and Scripting

Help with matching pattern inside a file

I have a huge file that has roughly 30304 lines. I need to extract specific info from that file. For example, Box 1 > *aaaaaaaajjjj* > hbbvjvj > jdnnfddllll > *dgdfhfekwjh* Box 2 > *aaaaaaa'aj'jjj* > dse hkjuejef bfdw > dyeee > dsewq > *dgdfhfekwjh* >feweiuei Box 3 > *aaaa"aaaaj"jjj* >... (25 Replies)
Discussion started by: Ernst
25 Replies

5. Shell Programming and Scripting

Get matching string pattern from a file

Hi, file -> temp.txt cat temp.txt /home/pradeep/123/a_asp.html /home/pradeep/123/a_asp1.html /home/pradeep/435/a_asp2.html /home/pradeep/arun/abc/a_dfr.html /home/pradeep/arun/123/a_kir.html /home/pradeep/123/arun/a_dir.html .... .... .. i need to get a_*.html(bolded strings... (4 Replies)
Discussion started by: pradebban
4 Replies

6. Shell Programming and Scripting

AWK match $1 $2 pattern in file 1 to $1 $2 pattern in file2

Hi, I have 2 files that I have modified to basically match each other, however I want to determine what (if any) line in file 1 does not exist in file 2. I need to match column $1 and $2 as a single string in file1 to $1 and $2 in file2 as these two columns create a match. I'm stuck in an AWK... (9 Replies)
Discussion started by: right_coaster
9 Replies

7. Shell Programming and Scripting

awk pattern matching and shell issue.

Please help me in this issue. I am unable to get the job,seems the awk not browsing the files. Please find my tries below. I have attached two files : 1.tobesearched.txt - a glimpse of a huge log file. 2.searchstring.txt - searching keys. these are the two scripts i tried writing: ... (7 Replies)
Discussion started by: deboprio
7 Replies

8. Shell Programming and Scripting

awk - writing matching pattern to a new file and deleting it from the current file

Hello , I have comma delimited file with over 20 fileds that i need to do some validations on. I have to check if certain fields are null and then write the line containing the null field into a new file and then delete the line from the current file. Can someone tell me how i could go... (2 Replies)
Discussion started by: goddevil
2 Replies

9. UNIX for Dummies Questions & Answers

How to append portion of a file content to another file when a certain pattern is matching?

Hi ladies and gentleman.. I have two text file with me. I need to replace one of the file content to another file if one both files have a matching pattern. Example: text1.txt: ABCD 1234567,HELLO_WORLDA,HELLO_WORLDB DCBA 3456789,HELLO_WORLDE,HELLO_WORLDF text2.txt: XXXX,ABCD... (25 Replies)
Discussion started by: bananamen
25 Replies

10. Shell Programming and Scripting

Awk: Matching Pattern From other file with length

Hi, I have input file whose first column needs(match.txt) to be matched with the first column of the input file with min & max length as defined in match.txt. But conditions are not matching. Please help on the changes in the code below as for multiple enteries in match.txt complete match.txt will... (3 Replies)
Discussion started by: siramitsharma
3 Replies
GREP(1) 						      General Commands Manual							   GREP(1)

NAME
grep, g - search a file for a pattern SYNOPSIS
grep [ option ... ] pattern [ file ... ] g [ option ... ] pattern [ file ... ] DESCRIPTION
Grep searches the input files (standard input default) for lines that match the pattern, a regular expression as defined in regexp(7) with the addition of a newline character as an alternative (substitute for |) with lowest precedence. Normally, each line matching the pattern is `selected', and each selected line is copied to the standard output. The options are -c Print only a count of matching lines. -h Do not print file name tags (headers) with output lines. -e The following argument is taken as a pattern. This option makes it easy to specify patterns that might confuse argument parsing, such as -n. -i Ignore alphabetic case distinctions. The implementation folds into lower case all letters in the pattern and input before interpre- tation. Matched lines are printed in their original form. -l (ell) Print the names of files with selected lines; don't print the lines. -L Print the names of files with no selected lines; the converse of -l. -n Mark each printed line with its line number counted in its file. -s Produce no output, but return status. -v Reverse: print lines that do not match the pattern. -f The pattern argument is the name of a file containing regular expressions one per line. -b Don't buffer the output: write each output line as soon as it is discovered. Output lines are tagged by file name when there is more than one input file. (To force this tagging, include /dev/null as a file name argument.) Care should be taken when using the shell metacharacters $*[^|()= and newline in pattern; it is safest to enclose the entire expression in single quotes '...'. An expression starting with '*' will treat the rest of the expression as literal characters. G invokes grep with -n and forces tagging of output lines by file name. If no files are listed, it searches all files matching *.C *.b *.c *.h *.m *.cc *.java *.cgi *.pl *.py *.tex *.ms SOURCE
/src/cmd/grep /bin/g SEE ALSO
ed(1), awk(1), sed(1), sam(1), regexp(7) DIAGNOSTICS
Exit status is null if any lines are selected, or non-null when no lines are selected or an error occurs. GREP(1)
All times are GMT -4. The time now is 08:32 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy