Opening a directory WITHOUT using 'opendir' and 'readdir'

skywalker27182 · 11-15-2003, 08:09 AM

Hi,
i am trying to write a program in 'C' (on RedHat 9) that lists all the files in a directory using only 'open' and 'read' and its details like space, inode no, etc. i remember reading in a book that UNIX treats all directories as normal files. so it is possible, right? but i couldn't do it. i saw in Ritchie's book on 'C' that 'readdir' and 'opendir' does use 'read' and 'open'. but it also uses 'malloc'. someone please tell me why and how to go about the program

ToniT · 11-15-2003, 02:10 PM

The striucture of the actual directory entry is dependant of the underlying filesystem. You do want to use readdir(3) or if you want a closer (linux spesific) interface, you can use open(2) and getdents(2) to read the contents of the directory. The read(2) gives you a 'EISDIR fd refers to a directory.' error if you try to access the directory directly.

coldfusion · 11-16-2003, 01:32 PM

you could use exec

you could do something like this:

execl("/bin/ls","/bin/ls","/",NULL);

though, if i recall correctly, exec will take over your program with "ls"

:edited: mistyped the execl