Very Computer

by **Ross Hayd** » Thu, 05 Jun 1997 04:00:00

I'm looking for a C algorithm to convert relative paths to an absolute
path.

For instance, I want to resolve "/usr/bin/X11/../ls" into "/usr/bin/ls."
But I would also like to generally clean up a path as well; eg.
"/usr/bin//ls" to "/usr/bin/ls," and so on.

Years ago I saw an algorithm to do this, posted here, but I have since
lost the darn thing.

Thanks for any ideas,
RH

by **Dr. Bor** » Thu, 05 Jun 1997 04:00:00

> I'm looking for a C algorithm to convert relative paths to an absolute
> path.

> For instance, I want to resolve "/usr/bin/X11/../ls" into "/usr/bin/ls."
> But I would also like to generally clean up a path as well; eg.
> "/usr/bin//ls" to "/usr/bin/ls," and so on.

> Years ago I saw an algorithm to do this, posted here, but I have since
> lost the darn thing.

Howdy Ross,

I was investigating the subject the other day and I found a function
that can do that, I think it is a GNU-specific function so you can
find a source for it on any FTP site carrying GNU software.

---------------------------------------------------------------------------
NAME
realpath - returns the canonicalized absolute pathname.

SYNOPSIS
#include <sys/param.h>
#include <unistd.h>

char *realpath(char *path, char resolved_path[]);

DESCRIPTION
realpath expands all symbolic links and resolves references to '/./', '/../'
and extra '/' characters in the null terminated string named by path and
stores the canonicalized absolute pathname in the buffer of size MAXPATHLEN
named by resolved_path. The resulting path will have no symbolic link, '/./'
or '/../' components.
[ THE REST SNIPPED ]
-----------------------------------------------------------------------------

--

#include <disclaimer.h> | *Good pings come in small packets*
Vancouver | Windows: for IQs smaller than 95
British Columbia | SIGSIG -- signature too long (core dumped)

by **Alan S. Gree** » Tue, 10 Jun 1997 04:00:00

> > I'm looking for a C algorithm to convert relative paths to an absolute
> > path.

> > For instance, I want to resolve "/usr/bin/X11/../ls" into "/usr/bin/ls."
> > But I would also like to generally clean up a path as well; eg.
> > "/usr/bin//ls" to "/usr/bin/ls," and so on.

> > Years ago I saw an algorithm to do this, posted here, but I have since
> > lost the darn thing.

> Howdy Ross,

> I was investigating the subject the other day and I found a function
> that can do that, I think it is a GNU-specific function so you can
> find a source for it on any FTP site carrying GNU software.

I don't think its GNU specific. I found it in standard C library on
HP-UX and Unixware.

- Show quoted text -

> ---------------------------------------------------------------------------
> NAME
> realpath - returns the canonicalized absolute pathname.

> SYNOPSIS
> #include <sys/param.h>
> #include <unistd.h>

> char *realpath(char *path, char resolved_path[]);

> DESCRIPTION
> realpath expands all symbolic links and resolves references to '/./', '/../'
> and extra '/' characters in the null terminated string named by path and
> stores the canonicalized absolute pathname in the buffer of size MAXPATHLEN
> named by resolved_path. The resulting path will have no symbolic link, '/./'
> or '/../' components.
> [ THE REST SNIPPED ]
> -----------------------------------------------------------------------------

> --

> #include <disclaimer.h> | *Good pings come in small packets*
> Vancouver | Windows: for IQs smaller than 95
> British Columbia | SIGSIG -- signature too long (core dumped)

--
Alan S. Greer /\/\o/\/\

Very Computer

Relative path to Absolute path

Relative path to Absolute path

Relative path to Absolute path

Relative path to Absolute path