Hi all,
I want a regular expression that will check for the space.
I mean, it should accept everything but no space should be there in the variable.
e.g. var1="aaaa" >>> OK
var2='aaa vv' >> Not OK
So it should not validate the second variable.
Please help.
Thanks in Advance.... (3 Replies)
Hello, I'm searching for a proper way to let the kernel space ISR(implemented in a kernel module) wake up a user space thread on a hardware interrupt.
Except for sending a real-time signal, is it possible to use a semaphore?
I've searched it on google, but it seems impossible to share a... (0 Replies)
Hi,
I have red hat enterprise 4. I would like to add more space on my lvm from the first partition that is not lvm type.
Here's the config
# fdisk -l
Disk /dev/sda: 73.4 GB, 73406611456 bytes
255 heads, 63 sectors/track, 8924 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes... (6 Replies)
Good afternoon! Im new at scripting and Im trying to write a script to
calculate total space, total used space and total free space in filesystem names matching a keyword (in this one we will use keyword virginia). Please dont be mean or harsh, like I said Im new and trying my best. Scripting... (4 Replies)
Hello,
$ ] && echo "ok" || echo "error";
error
$ ]] && echo "ok" || echo "error";
error
$ ]] && echo "ok" || echo "error";
ok
$
It seems that \d , , and are not the same.According to the regular expression reference, \d , , and have the same meaning, which represent a digit, but why... (8 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)
I just wrote a modsecurity rule that blocks execution on "cat /etc/passwd" from webshell. But when I use
cat /etc/passwd
it works. Ie when I add space after cat. What I need is a regular expression to ignore additional space than the first single space after cat. (2 Replies)
Hi,
I run Fedora 17.
I created a physical volume of 30GB on a disk with 60GB of space so there is 30GB of free space. On the physical volume, I created my volume group and logical volumes. I assigned all the space in the physical volume to my volume group. I need to add the 30GB of free space... (1 Reply)
Hi,
I have a space delimited text file but I only want to change the first space to a tab and keep the rest of the spaces intact. How do I go about doing that? Thanks! (3 Replies)
Hi All.
Attached are two files.
I ran a query and have the output as in the file with name "FILEWITHFOURRECORDS.txt "
I didn't want all the spaces between the columns so I squeezed the spaces with the "tr" command and also added a carriage return at the end of every line.
But in two... (3 Replies)
Discussion started by: sparks
3 Replies
LEARN ABOUT PLAN9
grep
GREP(1) General Commands Manual GREP(1)NAME
grep - search a file for a pattern
SYNOPSIS
grep [ option ... ] pattern [ file ... ]
DESCRIPTION
Grep searches the input files (standard input default) for lines (with newlines excluded) that match the pattern, a regular expression as
defined in regexp(6). 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.
-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.
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 '...'.
SOURCE
/sys/src/cmd/grep.c
SEE ALSO ed(1), awk(1), sed(1), sam(1), regexp(6)DIAGNOSTICS
Exit status is null if any lines are selected, or non-null when no lines are selected or an error occurs.
GREP(1)