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BSD 2.11 - man page for getmntopts (bsd section 3)

GETMNTOPTS(3)				       Library Functions Manual 				GETMNTOPTS(3)

NAME
getmntopts - scan mount options
SYNOPSIS
#include <mntopts.h> void getmntopts(options, mopts, flagp) char *options; struct mntopt *mopts; int *flagp
DESCRIPTION
The getmntopts() function takes a comma separated option list and a list of valid option names, and computes the bitmask corresponding to the requested set of options. The string options is broken down into a sequence of comma separated tokens. Each token is looked up in the table described by mopts and the bits in the word referenced by flagp are updated. The flag word is not ini- tialized by getmntopt. The table, mopts, has the following format: struct mntopt { char *m_option; /* option name */ int m_inverse; /* is this a negative option, eg "dev" */ int m_flag; /* bit to set, eg MNT_RDONLY */ }; The members of this structure are: m_option the option name, for example ``suid''. m_inverse tells getmntopts that the name has the inverse meaning of the bit. For example, ``suid'' is the string, whereas the mount flag is MNT_NOSUID. In this case, the sense of the string and the flag are inverted, so the m_inverse flag should be set. m_flag the value of the bit to be set or cleared in the flag word when the option is recognized. The bit is set when the option is discovered, but cleared if the option name was preceded by the letters ``no''. The m_inverse flag causes these two operations to be reversed. Each of the user visible MNT_ flags has a corresponding MOPT_ macro which defines an appropriate struct mntopt entry. To simplify the program interface and ensure consistency across all programs, a general purpose macro, MOPT_STDOPTS, is defined which contains an entry for all the generic VFS options. In addition, the macros MOPT_FORCE and MOPT_UPDATE exist to enable the MNT_FORCE and MNT_UPDATE flags to be set. Finally, the table must be terminated by an entry with a NULL first element.
EXAMPLES
Most commands will use the standard option set. Local filesystems which support the MNT_UPDATE flag, would also have an MOPT_UPDATE entry. This can be declared and used as follows: #include "mntopts.h" struct mntopt mopts[] = { MOPT_STDOPTS, MOPT_UPDATE, { NULL } }; ... mntflags = 0; ... getmntopts(options, mopts, &mntflags) ...
DIAGNOSTICS
The getmntopts function displays an error message and exits if an unrecognized option is encountered.
SEE ALSO
err(3), mount(8)
HISTORY
The getmntopts function appeared in 4.4BSD. 4.4 Berkeley Distribution January 16, 1996 GETMNTOPTS(3)


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