query about glib c setmntent function

Question

I have seen something like

setmntent(MOUNTED, "r");

What is the significance of MOUNTED? Is it a keyword? Macro?

After reading the man page of setmntent, I was of the opinion that the first argument to setmntentis file* which could be /etc/mtab or /proc/mounts. But this MOUNTED word has confused me.

Any help?

Answer 1

They are Macros in mmtent.h.

/* File listing canonical interesting mount points.  */
#define MNTTAB      _PATH_MNTTAB    /* Deprecated alias.  */

/* File listing currently active mount points.  */
#define MOUNTED     _PATH_MOUNTED   /* Deprecated alias.  */

Defines the type struct mntent and the macros MNTTAB, MOUNTED, MNTTYPE_, MNTOPT_, and declares the functions setmntent, getmntent, getmntent_r, addmntent, endmntent, hasmntopt.

The macros FSTAB, MNTTAB, and MOUNTED define a Path, but they are an deprecated alias and _PATH_MNTTAB and _PATH_MOUNTED should be used.

#define _PATH_FSTAB "/etc/fstab" (fstab.h)

#define _PATH_MOUNTED "/etc/mtab" (ie. paths.h of glibc)

see Mount-Information.