Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Validating IP address.
Top Forums Shell Programming and Scripting Validating IP address. Post 302217147 by era on Tuesday 22nd of July 2008 04:05:24 AM
Old 07-22-2008
As a stylistic issue, I would dissuade from the use of grep -c and [ xxx -eq 0 ] -- especially on $? -- in favor of something like

Code:
if ! echo "$ipadd" | grep -E '...' >/dev/null; then
  echo -e "*** Bad ..." >&2
  exit 2
fi

Also note the redirection of the error message to file descriptor 2. You might want to add $0 to the beginning of the error message as well.

The use of {1} in the regular expression is obviously redundant. In order to reduce backtracking, you might want to use [01][0-9]{0,2} to cover all strings beginning with 0 or 1 in one go, aand adjust the subsequent expression accordingly.
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

validating dates

This is what I have to check date entries in an interactive script with the end users... I use this to build control cards for a reporting utility supplied by a software vendor. I also want to check to make sure its a valid day based on the month (ie 30days has sept, april, june and Nov..)... ... (2 Replies)
Discussion started by: MizzGail
2 Replies

2. Programming

validating input

how do i validate y script so that it only accepts values between 1 and 3 and against any character input, cause at the moment i can only validate against numbers outside 1 and 3 but not characters cheers (4 Replies)
Discussion started by: ruffenator
4 Replies

3. UNIX for Dummies Questions & Answers

validating userid

What's wrong with this syntax? It's part of my 'if' statement but it doesn't seem to pass and it keeps going to the 'else' part. I thought it says that userid must start with a non-numeric character and is between 6 and 10 characters long (alphanumeric). $userid|grep -Eq '^?\{6,10\}+$' if... (2 Replies)
Discussion started by: giannicello
2 Replies

4. Shell Programming and Scripting

Validating $1 and $2 before using

Hi there, I'm trying to validate my $1 and $2 before I use them in the sqlplus update, I think I have the validation rules set correctly??? however when I test my script, it jumps straight into the sql. It doesn't seem to validate the vars....even when I know they are incorrect. if ; then ... (6 Replies)
Discussion started by: nhatch
6 Replies

5. Shell Programming and Scripting

validating 10. IP address any way possible

HELP: validating IP addresses any way possible -------------------------------------------------------------------------------- I am trying to validate input from the user in a script. I thought is was easy to do using regular expressions but I can't figure out how to use REs in a... (1 Reply)
Discussion started by: nrodolfich
1 Replies

6. UNIX for Dummies Questions & Answers

Panic kernal-mode address fault on user address 0x14

:) Firstly Hi all!!, im NEW!! and on here hoping that someone might be able to offer me some help... i have a server that keeps crashing every few days with the error message: PANIC KERNAL-MODE ADDRESS FAULT ON USER ADDRESS 0X14 KERNAL PAGE FAULT FROM (CS:EIP)=(100:EF71B5BD) EAX=EF822000... (10 Replies)
Discussion started by: Twix
10 Replies

7. UNIX for Dummies Questions & Answers

Validating a file

Pardon my ignorance but I am lost on how to do this I have a file called "Sample.txt", it is pipe delimited, it should have 13 fields. But some of the records do not, I would like to set up a shell script where I can pass in a parameter "Sample.txt" and it would split the file into records... (2 Replies)
Discussion started by: dgeehot
2 Replies

8. Shell Programming and Scripting

awk for validating

HI, I am trying to write a validation script as below awk '($1=="ABC"&&$2="XYZ" ,then check the value in $8,$10 these columns should not be null. so their should be some corresponding value n the $8 and $10 column,if their is no value the script has to give error saying that at a... (2 Replies)
Discussion started by: gaur.deepti
2 Replies

9. Shell Programming and Scripting

validating(pingable or not) remote ip address in shell script

i need to verify whether the ip adress given as input to the shell script is pingable or not... that is whether the ip is alive and responding.. ping $ip_adress the above wont work in script because the execution is continuous... so the shell script keeps will dwell in this pinging process...... (8 Replies)
Discussion started by: vivek d r
8 Replies

10. UNIX for Advanced & Expert Users

C program to detect duplicate ip address if any after assigning ip address to ethernet interface

Hi , Could someone let me know how to detect duplicate ip address after assigning ip address to ethernet interface using c program (3 Replies)
Discussion started by: Gopi Krishna P
3 Replies

LEARN ABOUT ULTRIX

zgrep

ZGREP(1)						      General Commands Manual							  ZGREP(1)

NAME

       zgrep - search possibly compressed files for a regular expression

SYNOPSIS

       zgrep [ grep_options ] [ -e ] pattern filename...

DESCRIPTION

       Zgrep  invokes  grep  on  compressed  or  gzipped  files.   These  grep	options  will  cause  zgrep  to  terminate  with  an  error  code:
       (-[drRzZ]|--di*|--exc*|--inc*|--rec*|--nu*).  All other options specified are passed directly to grep.  If no file is specified,  then  the
       standard input is decompressed if necessary and fed to grep.  Otherwise the given files are uncompressed if necessary and fed to grep.

       If the GREP environment variable is set, zgrep uses it as the grep program to be invoked.

EXIT CODE

       2 - An option that is not supported was specified.

AUTHOR

       Charles Levert (charles@comm.polymtl.ca)

SEE ALSO

       grep(1), gzexe(1), gzip(1), zdiff(1), zforce(1), zmore(1), znew(1)

																	  ZGREP(1)
All times are GMT -4. The time now is 01:03 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy