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Diffstat (limited to 'man/man2/getxattr.2')
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diff --git a/man/man2/getxattr.2 b/man/man2/getxattr.2 new file mode 100644 index 0000000..813873e --- /dev/null +++ b/man/man2/getxattr.2 @@ -0,0 +1,123 @@ +.\" +.\" Extended attributes system calls manual pages +.\" +.\" (C) Andreas Gruenbacher, February 2001 +.\" (C) Silicon Graphics Inc, September 2001 +.\" +.TH GETXATTR 2 "Extended Attributes" "Dec 2001" "System calls" +.SH NAME +getxattr, lgetxattr, fgetxattr \- retrieve an extended attribute value +.SH SYNOPSIS +.fam C +.nf +.B #include <attr/xattr.h> +.sp +.BI "ssize_t getxattr (const char\ *" path ", const char\ *" name ", +.BI "\t\t\t\t void\ *" value ", size_t " size ); +.BI "ssize_t lgetxattr (const char\ *" path ", const char\ *" name ", +.BI "\t\t\t\t void\ *" value ", size_t " size ); +.BI "ssize_t fgetxattr (int " filedes ", const char\ *" name ", +.BI "\t\t\t\t void\ *" value ", size_t " size ); +.fi +.fam T +.SH DESCRIPTION +Extended attributes are +.IR name :\c +.I value +pairs associated with inodes (files, directories, symlinks, etc). +They are extensions to the normal attributes which are associated +with all inodes in the system (i.e. the +.BR stat (2) +data). +A complete overview of extended attributes concepts can be found in +.BR attr (5). +.PP +.B getxattr +retrieves the +.I value +of the extended attribute identified by +.I name +and associated with the given +.I path +in the filesystem. +The length of the attribute +.I value +is returned. +.PP +.B lgetxattr +is identical to +.BR getxattr , +except in the case of a symbolic link, where the link itself is +interrogated, not the file that it refers to. +.PP +.B fgetxattr +is identical to +.BR getxattr , +only the open file pointed to by +.I filedes +(as returned by +.BR open (2)) +is interrogated in place of +.IR path . +.PP +An extended attribute +.I name +is a simple NULL-terminated string. +The name includes a namespace prefix \- there may be several, disjoint +namespaces associated with an individual inode. +The value of an extended attribute is a chunk of arbitrary textual or +binary data of specified length. +.PP +An empty buffer of +.I size +zero can be passed into these calls to return the current size of the +named extended attribute, which can be used to estimate the size of a +buffer which is sufficiently large to hold the value associated with +the extended attribute. +.PP +The interface is designed to allow guessing of initial buffer +sizes, and to enlarge buffers when the return value indicates +that the buffer provided was too small. +.SH RETURN VALUE +On success, a positive number is returned indicating the size of the +extended attribute value. +On failure, \-1 is returned and +.I errno +is set appropriately. +.PP +If the named attribute does not exist, or the process has no access to +this attribute, +.I errno +is set to ENOATTR. +.PP +If the +.I size +of the +.I value +buffer is too small to hold the result, +.I errno +is set to ERANGE. +.PP +If extended attributes are not supported by the filesystem, or are disabled, +.I errno +is set to ENOTSUP. +.PP +The errors documented for the +.BR stat (2) +system call are also applicable here. +.SH AUTHORS +Andreas Gruenbacher, +.RI < a.gruenbacher@computer.org > +and the SGI XFS development team, +.RI < linux-xfs@oss.sgi.com >. +Please send any bug reports or comments to these addresses. +.SH SEE ALSO +.BR getfattr (1), +.BR setfattr (1), +.BR open (2), +.BR stat (2), +.BR setxattr (2), +.BR listxattr (2), +.BR removexattr (2), +and +.BR attr (5). |