How to count unique strings

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting How to count unique strings
# 1  
Old 07-30-2009
How to count unique strings

How do I count the total number of unique strings from a file using Perl? Any help is appreciated..
# 2  
Old 07-30-2009
Assuming by unique you mean 100% unique, and things like case or white space are included in the uniqueness:

use strict;
use warnings;
my %unique;
open my $FH, '/path/to/your/file' or die "$!";
while(<$FH>) {
    chomp;#<-- remove this line if the record seperator should be incuded
close $FH;
foreach my $line (keys %unique) {
     print "$line = $unique{$line}\n";

Next time some effort on your part to first try and solve your programming requirements would be nice to see.
# 3  
Old 07-30-2009
Definitely. Thanks a lot.
# 4  
Old 07-30-2009
I'm not sure what happened in the code I posted, but this line:


should be:


So it displays the count of each unique line
# 5  
Old 07-30-2009
yes, I got an error message "Useless use of hash element in void context ....filename...


---------- Post updated at 02:40 PM ---------- Previous update was at 02:20 PM ----------

I've made changes to the code to handle utf8 as :--

use encoding 'utf8';

my %unique;
# my $unique;
my $line;

open my $FH, "<:encoding(utf8)", "$ARGV[0]" or die "Can't open file $ARGV[0]: $!";

while(<$FH>) {
close $FH;
foreach my $line (keys %unique) {
print "$line = $unique{$line}\n";

However, I am getting the message....

2 files to edit.

I don't know this.
# 6  
Old 07-30-2009
is the message coming from die or when you print the hash or something else? That sure is not any perl error or warning I have ever seen.
# 7  
Old 07-31-2009
Thanks a lot.
I worked.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. UNIX for Beginners Questions & Answers

Count unique column

Hello, I am trying to count unique rows in my file based on 4 columns (2-5) and to output its frequency in a sixth column. My file is tab delimited My input file looks like this: Colum1 Colum2 Colum3 Colum4 Coulmn5 1.1 100 100 a b 1.1 100 100 a c 1.2 200 205 a d 1.3 300 301 a y 1.3 300... (6 Replies)
Discussion started by: nans
6 Replies

2. UNIX for Beginners Questions & Answers

Count unique words

Dear all, I would like to know how to list and count unique words in thousands number of text files. Please help me out thanks in advance (9 Replies)
Discussion started by: imranrasheedamu
9 Replies

3. Shell Programming and Scripting

Count occurrence of column one unique value having unique second column value

Hello Team, I need your help on the following: My input file a.txt is as below: 3330690|373846|108471 3330690|373846|108471 0640829|459725|100001 0640829|459725|100001 3330690|373847|108471 Here row 1 and row 2 of column 1 are identical but corresponding column 2 value are... (4 Replies)
Discussion started by: angshuman
4 Replies

4. Shell Programming and Scripting

Count of unique lines in field 4

When I use the below awk to count the unique lines in $4 for the input it seems to work. The answer is 3 because $4 is only unique 3 times in all the entries. However, when I use the same on actual data I get 56,536 and I know the answer should be 56,548. My question is there a better way to... (8 Replies)
Discussion started by: cmccabe
8 Replies

5. Shell Programming and Scripting

awk to count using each unique value

Im looking for an awk script that will take the unique values in column 5, then print and count the unique values in column 6. CA001011500 11111 11111 -9999 201301 AAA CA001012040 11111 11111 -9999 201301 AAA CA001012573 11111 11111 -9999 201301 BBB CA001012710 11111 11111 -9999 201301... (4 Replies)
Discussion started by: ncwxpanther
4 Replies

6. Shell Programming and Scripting

Command to show unique strings in two files

how to display the unique strings in two files using shell script or commands. I tried diff and cmp but it shows the entire line, i need only the mismatched strings. File1: sat,sun,mon,tue rose,lilly,lotus white,red,blue,green,pink File2: sat,sun,mon,tue rose,sunflower,lotus... (4 Replies)
Discussion started by: Arun_Linux
4 Replies

7. Shell Programming and Scripting

calculating unique strings values

Hi, Im looking for a script which will calculate the unique strings column 2 & 3 values in a log as mentioned in example eg:- bag 12 12 bag 18 15 bags 15 13 bags 15 14 blazer 24 24 blazer 33 32 boots 19 15 Result should be:- bag 30 27 bags 30 27... (9 Replies)
Discussion started by: Paulwintech
9 Replies

8. Shell Programming and Scripting

Unique count from flat file

Hello Guys I have a flat file with '|~|' delimited When I use to record count using below command awk -FS"+" ' {print $colno}' filename | wc -l the count is fine But when I am trying to find the unique number of record the o/p is always 1 awk -FS"+" ' {print $colno}'... (11 Replies)
Discussion started by: Pratik4891
11 Replies

9. Shell Programming and Scripting

count identical strings print last row and count

I have a sorted file like: Apple 3 Apple 5 Apple 8 Banana 2 Banana 3 Grape 31 Orange 7 Orange 13 I'd like to search $1 and if $1 is not the same as $1 in the previous row print that row and print the number of times $1 was found. so the output would look like: Apple 8 3 Banana... (2 Replies)
Discussion started by: dcfargo
2 Replies

10. UNIX for Dummies Questions & Answers

Finding Unique strings which match pattern

I need to grep for a pattern in a file. Files are huge and have several repeated occurances of the strings which match pattern. I just need the strings which contain the pattern in the output. For eg. The contents of my file are as follows. The pattern I want to match by is ABCD ... (5 Replies)
Discussion started by: tektips
5 Replies
Login or Register to Ask a Question