the spaceship operator, <=>, is a comparison function, for numeric data only. It compares elements in the input array, @unsorted. The output of the sort call is written to the array @sorted. If no comparison function statement was entered (a blank), then sort works on the @unsoted array as letters of the alphabet, not numbers.
$a and $b are individual elements in the unosrted array - in this case numbers
If element $a is equal to element $b, then it returns 0; if $a is less than $b it returns -1; if $a is greater it returns +1 .
So the general statement is:
Internally perl sort calls a standard C library function, qsort for doing the comparisons and reordering over and entire array -or at least it did years ago. qsort(3): sort array - Linux man page
These 3 Users Gave Thanks to jim mcnamara For This Post:
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Hi Everyone,
# cat a.txt
a;b;c;64O
a;b;c;d;ee;f
# cat a.pl
#!/usr/bin/perl
use strict;
use warnings;
my $tmp3 = ",,a,,b,,c,,d,,e,,f,,";
open(my $FA, "a.txt") or die "$!";
while(<$FA>) {
chomp;
my @tmp=split(/\;/, $_);
if ( ($tmp =~ m/^(64O)/i) || ($tmp... (3 Replies)
I am running a program written in perl script and it is stopped with "Out of memory!" error. This is very strange because at the time then the program is aborted, it only used 4GB RAM and there are still 30GB free physical memory left in the system. I check the perl script and found the program... (3 Replies)
I need to sort the following file by the rhdiskpower devices in the last column:
Total_MB Free_MB OS_MB Name Failgroup Library Label UDID Product Redund Path
1024 851 1024 OCRVOT1_0000 OCRVOT1_0000 System UNKNOWN ... (3 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
I have seen something like this in a perl code:
$_ =~ s/__FD_PRN_/\\(/g
What does this "__FD_PRN_" means. I have searched google but was not able to find any info regarding this. Appreciate if some one can refer to a link for these characters. From comments/code it used to substitue "(" with... (3 Replies)
Hi All,
I have 2 pipe delimited files viz., file_old and file_new. I'm trying to compare these 2 files, and extract all the different rows between them into a new_file.
comm -3 < sort file_old < sort file_new > new_file
I am getting the below error:
-ksh: sort: cannot open
But if I do... (7 Replies)
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies
LEARN ABOUT SUNOS
qsort
qsort(3C) Standard C Library Functions qsort(3C)NAME
qsort - quick sort
SYNOPSIS
#include <stdlib.h>
void qsort(void *base, size_t nel, size_t width, int (*compar)(const void *, const void *));
DESCRIPTION
The qsort() function is an implementation of the quick-sort algorithm. It sorts a table of data in place. The contents of the table are
sorted in ascending order according to the user-supplied comparison function.
The base argument points to the element at the base of the table. The nel argument is the number of elements in the table. The width
argument specifies the size of each element in bytes. The compar argument is the name of the comparison function, which is called with two
arguments that point to the elements being compared.
The function must return an integer less than, equal to, or greater than zero to indicate if the first argument is to be considered less
than, equal to, or greater than the second argument.
The contents of the table are sorted in ascending order according to the user supplied comparison function.
USAGE
The qsort() function safely allows concurrent access by multiple threads to disjoint data, such as overlapping subtrees or tables.
EXAMPLES
Example 1: Program sorts.
The following program sorts a simple array:
#include <stdlib.h>
#include <stdio.h>
static int
intcompare(const void *p1, const void *p2)
{
int i = *((int *)p1);
int j = *((int *)p2);
if (i > j)
return(1);
if (i < j)
return (-1);
return(0);
}
int
main()
{
int i;
int a[10] = { 9, 8, 7, 6, 5, 4, 3, 2, 1, 0 };
size_t nelems = sizeof (a) / sizeof (int);
qsort((void *)a, nelems, sizeof (int), intcompare);
for (i = 0; i < nelems; i++) {
(void) printf("%d ", a[i]);
}
(void) printf("
");
return(0);
}
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Interface Stability |Standard |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO sort(1), bsearch(3C), lsearch(3C), string(3C), attributes(5), standards(5)NOTES
The comparison function need not compare every byte, so arbitrary data may be contained in the elements in addition to the values being
compared.
The relative order in the output of two items that compare as equal is unpredictable.
SunOS 5.10 6 Dec 2004 qsort(3C)