This is a conditional expression operator. The format is : condition ? expression1 : expression2.
If the condition is true, the result is expression1 else the result is expression2.
With our command we check the value of s1 (s1?). If s1 is true (s1 is not empty) we assign the contents of s1, a newline ("\n") and the current record ($0) to s1. If the condition is false (s1 is empty) we assign the current record ($0) to s1.
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=$0"\n"s
getline;print;print s
next
}1' fileko.tx
.
desired output: (8 Replies)
Hi there,
I have a text that I'm trying to format into something more readable. However, I'm stuck in the last step. I've searched and tried things over the internet with no avail.
OS: Mac
After parsing the original text that I won't put here, I managed to get something like this, but this... (8 Replies)
Discussion started by: Kibou
8 Replies
LEARN ABOUT CENTOS
if
if(n) Tcl Built-In Commands if(n)
__________________________________________________________________________________________________________________________________________________NAME
if - Execute scripts conditionally
SYNOPSIS
if expr1 ?then? body1 elseif expr2 ?then? body2 elseif ... ?else? ?bodyN?
_________________________________________________________________DESCRIPTION
The if command evaluates expr1 as an expression (in the same way that expr evaluates its argument). The value of the expression must be a
boolean (a numeric value, where 0 is false and anything is true, or a string value such as true or yes for true and false or no for false);
if it is true then body1 is executed by passing it to the Tcl interpreter. Otherwise expr2 is evaluated as an expression and if it is true
then body2 is executed, and so on. If none of the expressions evaluates to true then bodyN is executed. The then and else arguments are
optional "noise words" to make the command easier to read. There may be any number of elseif clauses, including zero. BodyN may also be
omitted as long as else is omitted too. The return value from the command is the result of the body script that was executed, or an empty
string if none of the expressions was non-zero and there was no bodyN.
EXAMPLES
A simple conditional:
if {$vbl == 1} { puts "vbl is one" }
With an else-clause:
if {$vbl == 1} {
puts "vbl is one"
} else {
puts "vbl is not one"
}
With an elseif-clause too:
if {$vbl == 1} {
puts "vbl is one"
} elseif {$vbl == 2} {
puts "vbl is two"
} else {
puts "vbl is not one or two"
}
Remember, expressions can be multi-line, but in that case it can be a good idea to use the optional then keyword for clarity:
if {
$vbl == 1 || $vbl == 2 || $vbl == 3
} then {
puts "vbl is one, two or three"
}
SEE ALSO
expr(n), for(n), foreach(n)
KEYWORDS
boolean, conditional, else, false, if, true
Tcl if(n)