ISDUID(3) | Library Functions Manual | ISDUID(3)

# NAME

`isduid` — disklabel UID test

# SYNOPSIS

System Utilities Library (libutil, -lutil)
`#include <util.h>`

int
`isduid`(char *duid, int dflags);

# DESCRIPTION

The `isduid`() function tests the string duid to see if it is a valid disklabel(8) UID. The dflags are specified using the same flags as used by opendev(3).

If the OPENDEV_PART flag is included in dflags, the disklabel UID must consist of a 16-character hexadecimal string. Otherwise the disklabel UID must consist of a 16-character hexadecimal string followed by a ‘.’ and a partition letter.

# RETURN VALUES

The `isduid`() function returns non-zero if duid is a valid DUID, otherwise zero is returned.

# SEE ALSO

opendev(3), disklabel(5), disklabel(8)

# HISTORY

The `isduid`() function first appeared in OpenBSD 4.9.

June 6, 2025 | Debian