A small C program for checking if a filesystem is mounted read-only.
This is just a wrapper around the statvfs call.
Only tested to work on Linux.
Compile with make. Edit the Makefile if necessary.
Move the resulting binary checkro to wherever you like.
checkro <mountpoint>
where <mountpoint> is the mount point of the filesystem that you wish to check.
If the filesystem is mounted read-only, it will print "1" to stdout, otherwise "0".
In both cases the exit status of the program is zero.
If there is an error determining the status of the file-system, an error message
is printed to stderr, and the exit status is non-zero.