'\" te
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.TH realpath 3C "9 Oct 2003" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
realpath \- resolve pathname
.SH SYNOPSIS
.LP
.nf
#include <stdlib.h>

\fBchar *\fR\fBrealpath\fR(\fBconst char *restrict\fR \fIfile_name\fR,
     \fBchar *restrict\fR \fIresolved_name\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBrealpath()\fR function derives, from the pathname pointed to by
\fIfile_name\fR, an absolute pathname that names the same file, whose
resolution does not involve "\fB\&.\fR", "\fB\&..\fR", or symbolic links. The
generated pathname is stored as a null-terminated string, up to a maximum of
{\fBPATH_MAX\fR} bytes (defined in \fBlimits.h\fR(3HEAD)), in the buffer
pointed to by \fIresolved_name\fR.
.SH RETURN VALUES
.sp
.LP
On successful completion, \fBrealpath()\fR returns a pointer to the resolved
name.  Otherwise, \fBrealpath()\fR returns a null pointer and sets \fBerrno\fR
to indicate the error, and the contents of the buffer pointed to by
\fIresolved_name\fR are left in an indeterminate state.
.SH ERRORS
.sp
.LP
The \fBrealpath()\fR function will fail if:
.sp
.ne 2
.mk
.na
\fB\fBEACCES\fR\fR
.ad
.RS 16n
.rt  
Read or search permission was denied for a component of \fIfile_name\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fBEINVAL\fR\fR
.ad
.RS 16n
.rt  
Either the \fIfile_name\fR or \fIresolved_name\fR argument is a null pointer.
.RE

.sp
.ne 2
.mk
.na
\fB\fBEIO\fR\fR
.ad
.RS 16n
.rt  
An error occurred while reading from the file system.
.RE

.sp
.ne 2
.mk
.na
\fB\fBELOOP\fR\fR
.ad
.RS 16n
.rt  
Too many symbolic links were encountered in resolving \fIfile_name\fR.
.RE

.sp
.ne 2
.mk
.na
\fB\fBELOOP\fR\fR
.ad
.RS 16n
.rt  
A loop exists in symbolic links encountered during resolution of the
\fIfile_name\fR argument.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENAMETOOLONG\fR\fR
.ad
.RS 16n
.rt  
The \fIfile_name\fR argument is longer than {\fBPATH_MAX\fR} or a pathname
component is longer than {\fBNAME_MAX\fR}.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOENT\fR\fR
.ad
.RS 16n
.rt  
A component of \fIfile_name\fR does not name an existing file or
\fIfile_name\fR points to an empty string.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOTDIR\fR\fR
.ad
.RS 16n
.rt  
A component of the path prefix is not a directory.
.RE

.sp
.LP
The \fBrealpath()\fR function may fail if:
.sp
.ne 2
.mk
.na
\fB\fBENAMETOOLONG\fR\fR
.ad
.RS 16n
.rt  
Pathname resolution of a symbolic link produced an intermediate result whose
length exceeds {\fBPATH_MAX\fR}.
.RE

.sp
.ne 2
.mk
.na
\fB\fBENOMEM\fR\fR
.ad
.RS 16n
.rt  
Insufficient storage space is available.
.RE

.SH USAGE
.sp
.LP
The \fBrealpath()\fR function operates on null-terminated strings.
.sp
.LP
Execute permission is required for all the directories in the given and the
resolved path.
.sp
.LP
The \fBrealpath()\fR function might fail to return to the current directory if
an error occurs.
.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
Interface StabilityStandard
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBgetcwd\fR(3C), \fBlimits.h\fR(3HEAD), \fBsysconf\fR(3C),
\fBattributes\fR(5), \fBstandards\fR(5)