Hi I already refer to doc but still blur especially on regexp. Appreciate if u can explain further.
Code:
local @ARGV = ($File); # puts $File into the array @ARGV
local $^I = $Bak_ext; # (Backup input file, output with original filename)
local $/ = undef; # read entire file at once
For backup file i think is much easier to understand. but one question is it necessary for us to have this line local $/ = undef;. What will happen if i remove it?
Code:
s/ # s/ = substitute operator
\A(.*?\n) # \A = match at only beginning of string
# () = grouping
# . = allow single char to match
# *? = match 0 or more time
# \n = newline
((?:\S+\s+){3}$Pattern\b.*?\n) # () = grouping
# ?: Non-capturing groupings
# \S+ Match a non-whitespace character 1 or more times
# \s+ Match a whitespace character 1 or more times
# {3}= Match exactly 3 times
# \b = Match a word boundary
# . = allow single char to match
# *? = match 0 or more time
# \n = newline
(.*?\n) # . = allow single char to match
# *? = match 0 or more time
# \n = newline
/$1$3$2/xos; #substitute with $1$3$2. XOS?
print #print balance line?
For code above, is it correct it do search n replace?(s/regexp/replacement/modifiers). Actually I still blur with the above regexp. Correct me if i'm wrong, is it the regexp match 3 times for the pattern? . I got confused what exactly it do.
For replacement line, is it $1$3$2 refer to line of the file? i tried to print out $1 to see the content but nothing happened.
I already google for XOS but no explaination about it. Hope someone can help.
I'm a bit new to regex and sed/perl stuff, so I would like to ask for some advice. I have tried several variations of scripts I've found on the net, but can't seem to get them to work out just right.
I have a file with the following information...
# Host 1
host 45583 {
filename... (4 Replies)
Hello, I have only recently begun with awk and need to write this:
I have an input consisting of a couple of letters, a space and a number followed by various other characters:
fiRcQ 9( )
klsRo 9( ) pause
fiRcQ 9( ) pause
klsRo continue 1
aPLnJ 62( )
fiRcQ continue 5
... and so on
I... (7 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
The assignment is to convert a text table to csv format. I've got the cleaning up done, but I need to swap two... (0 Replies)
I have some text:
<date>some_date</date>
<text>some_text</text>
<name>some_name<name>
and I want to transform it to smthng like that:
some_name on some_date: some_text
I've tried sed:
sed 's/<text>\(.*\)<\/text>
<name>\(.*\)<\/name>/\2 - \1/'
but it says unterminated... (13 Replies)
Hi
I'm quite new with linux.
Very simple, I need to swap every 2 lines in a file.
Example
INPUT:
a a a
b b b
x x x
y y y
s s s
t t t
OUTPUT:
b b b
a a a
y y y
x x x
t t t (5 Replies)
Hi All,
Sorry if this question has been posted elsewhere, but I'm hoping someone can help me! Bit of an AWK newbie here, but I'm learning (slowly!)
I'm trying to cobble a script together that will save me time (is there any other kind?), to swap two fields (one containing whitespace), with... (5 Replies)
Data file example
I look for primary and * to isolate the interesting slot number.
slot=`sed '/^primary$/,/\*/!d' filename | tail -1 | sed s'/*//' | awk '{print $1" "$2}'`
Now I want to get the Touch line for only the associate slot number, in this case, because the asterisk... (2 Replies)
How can you swap the first 4 line only, the rest will stay the same.
thanks
#!/bin/sh
line=4
awk -v var="$line" 'NR==var {
s=$0
getline;s=$0"\n"s
getline;print;print s
next
}1' fileko.tx
.
desired output: (8 Replies)
Hi there,
I have a text that I'm trying to format into something more readable. However, I'm stuck in the last step. I've searched and tried things over the internet with no avail.
OS: Mac
After parsing the original text that I won't put here, I managed to get something like this, but this... (8 Replies)
Discussion started by: Kibou
8 Replies
LEARN ABOUT FREEBSD
ddb
DDB(8) BSD System Manager's Manual DDB(8)NAME
ddb -- configure DDB kernel debugger properties
SYNOPSIS
ddb capture [-M -core] [-N -system] print
ddb capture [-M -core] [-N -system] status
ddb script scriptname
ddb script scriptname=script
ddb scripts
ddb unscript scriptname
ddb pathname
DESCRIPTION
The ddb utility configures certain aspects of the ddb(4) kernel debugger from user space that are not configured at compile-time or easily
via sysctl(8) MIB entries.
To ease configuration, commands can be put in a file which is processed using ddb as shown in the last synopsis line. An absolute pathname
must be used. The file will be read line by line and applied as arguments to the ddb utility. Whitespace at the beginning of lines will be
ignored as will lines where the first non-whitespace character is '#'.
OUTPUT CAPTURE
The ddb utility can be used to extract the contents of the ddb(4) output capture buffer of the current live kernel, or from the crash dump of
a kernel on disk. The following debugger commands are available from the command line:
capture [-M core] [-N system] print
Print the current contents of the ddb(4) output capture buffer.
capture [-M core] [-N system] status
Print the current status of the ddb(4) output capture buffer.
SCRIPTING
The ddb utility can be used to configure aspects of ddb(4) scripting from user space; scripting support is described in more detail in
ddb(4). Each of the debugger commands is available from the command line:
script scriptname
Print the script named scriptname.
script scriptname=script
Define a script named scriptname. As many scripts contain characters interpreted in special ways by the shell, it is advisable to
enclose script in quotes.
scripts
List currently defined scripts.
unscript scriptname
Delete the script named scriptname.
EXIT STATUS
The ddb utility exits 0 on success, and >0 if an error occurs.
EXAMPLES
The following example defines a script that will execute when the kernel debugger is entered as a result of a break signal:
ddb script kdb.enter.break="show pcpu; bt"
The following example will delete the script:
ddb unscript kdb.enter.break
For further examples, see the ddb(4) and textdump(4) manual pages.
SEE ALSO ddb(4), textdump(4), sysctl(8)HISTORY
The ddb utility first appeared in FreeBSD 7.1.
AUTHORS
Robert N M Watson
BUGS
Ideally, ddb would not exist, as all pertinent aspects of ddb(4) could be configured directly via sysctl(8).
BSD December 24, 2008 BSD
12-01-2008
. I got confused what exactly it do.