---
name: "Slurm::Hostlist"
section: "3pm"
platform: "linux"
package: "libslurm-perl"
version: "24.11.5-4"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/Slurm::Hostlist"
---

# Slurm::Hostlist(3pm)

Hostlist functions in libslurm

## NAME

Slurm::Hostlist - Hostlist functions in libslurm

## SYNOPSIS

```
 use Slurm;
 $hostnames = "node1,node[2-5,12]";
 $hl = Slurm::Hostlist::create($hostnames);
 $cnt = $hl->count;
 $hl->push("node21,node[27-34]");
 while($host = $hl->shift()) {
        print $host, "\n";
 }
 print $hl->ranged_string(), "\n";
```

## DESCRIPTION

The Slurm::Hostlist class is a wrapper of the hostlist functions in libslurm. This package is loaded and bootstrapped with package Slurm.

## METHODS

### $hl = Slurm::Hostlist::new($str);

Create a new hostlist from a string representation. Returns an opaque hostlist object. This is a **CLASS METHOD**.

The string representation ($str) may contain one or more hostnames or bracketed hostlists separated by either \`,' or whitespace. A bracketed hostlist is denoted by a common prefix followed by a list of numeric ranges contained within brackets: e.g. "tux\[0-5,12,20-25\]".

To support systems with 3-D topography, a rectangular prism may be described using two three digit numbers separated by "x": e.g. "bgl\[123x456\]". This selects all nodes between 1 and 4 inclusive in the first dimension, between 2 and 5 in the second, and between 3 and 6 in the third dimension for a total of 4\*4\*4=64 nodes.

If `$str` is omitted, and empty hostlist is created and returned.

### $cnt = $hl-\>count();

Return the number of hosts in the hostlist.

### $pos = $hl-\>find($hostname);

Searches hostlist `$hl` for the first host matching `$hostname` and returns position in list if found.

Returns -1 if host is not found.

### $cnt = $hl-\>push($hosts);

Push a string representation of hostnames onto a hostlist. The `$hosts` argument may take the same form as in **create()**.

Returns the number of hostnames inserted into the list,

### $cnt = $hl-\>push\_host($hostname);

Push a single host onto the hostlist hl.

This function is more efficient than **slurm\_hostlist\_push()** for a single hostname, since the argument does not need to be checked for ranges.

Return value is 1 for success, 0 for failure.

### $str = $hl-\>ranged\_string();

Return the string representation of the hostlist `$hl`. **ranged\_string()** will write a bracketed hostlist representation where possible.

### $host = $hl-\>shift();

Returns the string representation of the first host in the hostlist or \`undef' if the hostlist is empty or there was an error allocating memory. The host is removed from the hostlist.

### $hl-\>uniq();

Sort the hostlist `$hl` and remove duplicate entries.

## SEE ALSO

Slurm

## AUTHOR

This library is created by Hongjia Cao, \<hjcao(AT)nudt.edu.cn\> and Danny Auble, \<da(AT)llnl.gov\>. It is distributed with SLURM.

## COPYRIGHT AND LICENSE

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.4 or, at your option, any later version of Perl 5 you may have available.