I understood what you want, but to explain the ?, I read about it and fooled around, which might explain it a bit:
So it is as the description says, none or one occurence. Here it is a group of characters, but they interpret as single characters, not as a complete string.
Hi,
In some machines when i type "clear" it completely clears all the contents on that window but on some it simply scrolls up all the content.
How can i change this? (4 Replies)
:confused: some one please tell me where i can possibly find out what is unix 10.2 and the basic system functions of it is. I really need help! (1 Reply)
I'm an intern at a company that recently bought out another business. In doing so, they inherited a unix system that contains files which they need to retrieve. No one in the company, including myself, really understands or knows unix so please respond with the true assumption that I'm a unix... (1 Reply)
Good day, everyone!
Could anybody explain me the following situation.
If I'm running similar script:
Var="anna.kurnikova"
Var2="Anna Kurn"
echo $Var | tr -t "$Var" "$Var2"
Why the output is :
anna KurniKova
instead of Anna Kurnikova?
:confused:
Thank you in advance for any... (2 Replies)
Hi,
I was trying to learn forking in C in UNIX. Somehow i still haven't been able to get the concept well. I mean, i do understand that fork creates an exact replica of the parent (other than the fact that parent gets the process id of the child and child gets 0 when fork is called). This is the... (2 Replies)
Hi all,
How am I read a file, find the match regular expression and overwrite to the same files.
open DESTINATION_FILE, "<tmptravl.dat" or die "tmptravl.dat";
open NEW_DESTINATION_FILE, ">new_tmptravl.dat" or die "new_tmptravl.dat";
while (<DESTINATION_FILE>)
{
# print... (1 Reply)
Hi friends,
This is a small program built on the concept of shared memory. The producer is a separate program and process, and the consumer is a seperate program and process. Both are executed under the same user account. The producer takes some string from the user and adds that string to the... (1 Reply)
I don't even know where to start with this one. There is so much out there about different aspects of this. I am starting with a basic Ubuntu 11.04 install. Do I need to configure a DNS? I am a little confused about that. What do I need to do for a domain name? I have followed various tutorials,... (1 Reply)
Hello All,
I have a problem in counting number of process getting run with my current script name..
Here it is
ps -ef | grep $0 | grep -v grep
This display just one line with the PID, PPID and other details when i print it in the script.
But when I want to count the numbers in my... (11 Replies)
Is wc -c and wc -m same ?
Shellscript::cat file1
hello
Shellscript::cat file1 | wc -c
6
Shellscript::cat file1 | wc -m
6
Shellscript::file file1
file1: ASCII text
Shellscript::uname -a
Linux was85host 2.6.27.45-0.1-vmi #1 SMP 2010-02-22 16:49:47 +0100 i686 i686 i386 GNU/LinuxAtleast... (5 Replies)
Discussion started by: shellscripting
5 Replies
LEARN ABOUT ULTRIX
re_comp
regex(3) Library Functions Manual regex(3)Name
re_comp, re_exec - regular expression handler
Syntax
char *re_comp(s)
char *s;
re_exec(s)
char *s;
Description
The subroutine compiles a string into an internal form suitable for pattern matching. The subroutine checks the argument string against
the last string passed to
The subroutine returns 0 if the string s was compiled successfully; otherwise a string containing an error message is returned. If is
passed 0 or a null string, it returns without changing the currently compiled regular expression.
The subroutine returns 1 if the string s matches the last compiled regular expression, 0 if the string s failed to match the last compiled
regular expression, and -1 if the compiled regular expression was invalid (indicating an internal error).
The strings passed to both and may have trailing or embedded newline characters; they are terminated by nulls. The regular expressions
recognized are described in the manual entry for given the above difference.
Diagnostics
The subroutine returns -1 for an internal error.
The subroutine returns one of the following strings if an error occurs:
No previous regular expression
Regular expression too long
unmatched (
missing ]
too many () pairs
unmatched )
See Alsoed(1), ex(1), egrep(1), fgrep(1), grep(1)regex(3)