Login or Register to Ask a Question and Join Our Community


UNIX for Beginners Questions & Answers

Explain this IP Regex

Login to Discuss or Reply to this Discussion in Our Community

 
Thread Tools Search this Thread
Top Forums UNIX for Beginners Questions & Answers Explain this IP Regex
# 1  
Old 11-30-2016
Explain this IP Regex
Hi,guys
could anyone plz explain me this regex pattern for validating ip address
Code:
[0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])

# 2  
Old 11-30-2016
Theres a left parenthesis missing at the start. In regexes, | is the "alternation" or "OR" operator, so above reads "match a number consisting of"
Code:
[0-9]            a single digit                          OR
[1-9][0-9]       two digits not starting with a zero     OR 
1[0-9]{2}        three digits starting with a 1          OR
2[0-4][0-9]      200 - 249                               OR
25[0-5]          25 followed by 0 - 5

This number followed by a single literal dot ( \. ) should occur three times ( {3} ) plus once again (without dot).
This User Gave Thanks to RudiC For This Post:
Meeran Rizvi
# 3  
Old 11-30-2016
Thanks Rudic
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Sendmail K command regex: adding exclusion/negative lookahead to regex -a@MATCH

I'm trying to get some exclusions into our sendmail regular expression for the K command. The following configuration & regex works: LOCAL_CONFIG # Kcheckaddress regex -a@MATCH +<@+?\.++?\.(us|info|to|br|bid|cn|ru) LOCAL_RULESETS SLocal_check_mail # check address against various regex... (0 Replies)
Discussion started by: RobbieTheK
0 Replies

2. Shell Programming and Scripting

Perl, RegEx - Help me to understand the regex!

I am not a big expert in regex and have just little understanding of that language. Could you help me to understand the regular Perl expression: ^(?!if\b|else\b|while\b|)(?:+?\s+){1,6}(+\s*)\(*\) *?(?:^*;?+){0,10}\{ ------ This is regex to select functions from a C/C++ source and defined in... (2 Replies)
Discussion started by: alex_5161
2 Replies

3. UNIX for Dummies Questions & Answers

read regex from ID file, print regex and line below from source file

I have a file of protein sequences with headers (my source file). Based on a list of IDs (which are included in some of the headers), I'd like to print out only the specified sequences, with only the ID as header. In other words, I'd like to search source.txt for the terms in IDs.txt, and print... (3 Replies)
Discussion started by: pathunkathunk
3 Replies

4. Shell Programming and Scripting

Can someone explain this for me?

Can someone do me a favour and explain the following for me: ((r=$RANDOM%$n+1)) I know what $RANDOM does but what is % sign and what does it do with %$n+1? (2 Replies)
Discussion started by: bashily
2 Replies

5. Shell Programming and Scripting

anyone can explain this?

why the case 2 will happen ? , ' should stop the history substitution ,shouldn't it? case 1 # echo "123"|sed '/123/!d' 123 case 2 # echo "123 > 456 > 1 > "|sed '/123/!d' -bash: !d': event not found case 3 # echo "123 > 456 > 12 > "|sed '/123/'\!d 123 # bash --version (1 Reply)
Discussion started by: justlooks
1 Replies

6. Shell Programming and Scripting

need explain

Dear unix team i'm user for a system build on unix system ,so we need to run a lot of scripts not in one sission but every script on the associated terminal , so the script name = the name of the terminal which will run this script on it . and someone create a batch that make as below : 1- but... (4 Replies)
Discussion started by: fofatoti
4 Replies

7. Shell Programming and Scripting

Please explain this

cat $BDDATA/svucon$i_bal_dup_email.dat ; uuencode $dup_in $dup_out here svucon$i_bal_dup_email.dat ??? and uuencode ?? Please use and tags when posting code, data or logs etc. to preserve formatting and enhance readability, thanks. (2 Replies)
Discussion started by: Diddy
2 Replies

8. Shell Programming and Scripting

Can anyone please explain this??

cur_fy=`grep "CONSOL" $GLDATA/parms/cur_fiscalyear.lis | awk '{print $2}' Here i don't understand "CONSOL" and awk'{print$2) Please help me out cur_fiscalyear.lis contents : DL 2011 MOL 2011 MV 2011 SF 2010 CONSOL 2011 MVU 2011 (3 Replies)
Discussion started by: Diddy
3 Replies

9. Shell Programming and Scripting

Converting perl regex to sed regex

I am having trouble parsing rpm filenames in a shell script.. I found a snippet of perl code that will perform the task but I really don't have time to rewrite the entire script in perl. I cannot for the life of me convert this code into something sed-friendly: if ($rpm =~ /(*)-(*)-(*)\.(.*)/)... (1 Reply)
Discussion started by: suntzu
1 Replies

10. Shell Programming and Scripting

can anyone explain this?

:start /@~/{ h s/\(.*\)@~.*$/\1/ s/@~$// s/@~/\ /g p g s/.*@~\(.*\)/\1/ } //{ N s/\n/ / b start } (2 Replies)
Discussion started by: djkane
2 Replies
Login or Register to Ask a Question