Given a stdio FILE * pointer, is there a method by which I can discover the name of the (opened) file?
Given a stdio FILE * pointer, is there a method by which I can
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Given a stdio FILE * pointer, is there a method by which I can discover the name of the (opened) file?
It looks (from here) that on POSIX systems you can use fileno() to get the file descriptor from a FILE*, then use fstat to get the stat info from the file descriptor. The stat structure contains the device number and inode number. You can check the filesystem for files which match the inode. This will obviously take some time for a filesystem full of stuff.
The reason that this isn’t really possible (as explained in the linked article) is that a stream can have no filename if it’s something like stdin or stdout, or if it’s an open file that has been deleted. It can have multiple names because of hardlinks as well.
The linked article mentions this comp.lang.c FAQ which outlines the insolubility of this problem in brief.
EDIT: Thanks for the correction.