Escali 4.4 manual Appendix D Bracket expansion and grouping, Grouping

Appendix D Bracket expansion and grouping

To ease usage of Scali software on large cluster configuration, many of the command line utilities have bracket expansion and grouping functionality.

D-1 Bracket expansion

The following syntax applies:

<bracket>	== "["<number_or_range>[,<number_or_range>]*"]"
<number_or_range>	== <number> <from>-<to>[:<stride>]
<number>	== <digit>+
<from>	== <digit>+
<to>	== <digit>+
<stride>	== <digit>+
<digit>	== 0123456789

This is typically used to expand nodenames from a range, using from 1 to multi-dimensional numbering, or an explicit list.

If <to> or <from> contains leading zeros, then the expansion will contain leading zeros such that the width is constant and equal to the larger of the widths of <to> and <from>.

The syntax does not allow for negative numbers. <from> does not have to be less that <to>.

Examples:

n[0-2]

is equivalent to n0 n1 n2

n[00-10:3]

is equivalent to n00 n03 n06 n09

D-2 Grouping

Utilities that use scagroup will accept a group alias wherever a host name of hostlist i expected. The group alias will be resolved to a list of hostnames as specified in the file scagroup config file. If there exists a file .scagroup.conf in the users home directory, this will be used.

Otherwise, the system default file /opt/scali/etc/scagroup.conf will be used.

D-2.1 File format

Each group has the keyword group at the beginning of a line followed by a group alias and a list of hostnames included in the group. The list may itself contain previously defined group aliases which will be recursivly resolved. The host list may use bracket expressions which will be resolved as specified above.

The file may contain comments which is a line starting with # .

Examples:

group master n00 group slaves n[01-32] group all master slaves

Scali MPI Connect Release 4.4 Users Guide 62