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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:41:07 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-15 19:41:07 +0000
commit3af6d22bb3850ab2bac67287e3a3d3b0e32868e5 (patch)
tree3ee7a3ec64525911fa865bb984c86d997d855527 /man2/getdents.2
parentAdding debian version 6.05.01-1. (diff)
downloadmanpages-3af6d22bb3850ab2bac67287e3a3d3b0e32868e5.tar.xz
manpages-3af6d22bb3850ab2bac67287e3a3d3b0e32868e5.zip
Merging upstream version 6.7.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--man2/getdents.246
1 files changed, 25 insertions, 21 deletions
diff --git a/man2/getdents.2 b/man2/getdents.2
index 604a6ef..728d4d7 100644
--- a/man2/getdents.2
+++ b/man2/getdents.2
@@ -8,7 +8,7 @@
.\" Derived from 'readdir.2'.
.\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
.\"
-.TH getdents 2 2023-05-03 "Linux man-pages 6.05.01"
+.TH getdents 2 2024-02-25 "Linux man-pages 6.7"
.SH NAME
getdents, getdents64 \- get directory entries
.SH LIBRARY
@@ -18,23 +18,23 @@ Standard C library
.nf
.BR "#include <sys/syscall.h>" " /* Definition of " SYS_* " constants */"
.B #include <unistd.h>
-.PP
+.P
.BI "long syscall(SYS_getdents, unsigned int " fd \
", struct linux_dirent *" dirp ,
.BI " unsigned int " count );
-.PP
+.P
.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
.B #include <dirent.h>
-.PP
+.P
.BI "ssize_t getdents64(int " fd ", void " dirp [. count "], size_t " count );
.fi
-.PP
+.P
.IR Note :
glibc provides no wrapper for
.BR getdents (),
necessitating the use of
.BR syscall (2).
-.PP
+.P
.IR Note :
There is no definition of
.I struct linux_dirent
@@ -58,16 +58,16 @@ into the buffer pointed to by
The argument
.I count
specifies the size of that buffer.
-.PP
+.P
The
.I linux_dirent
structure is declared as follows:
-.PP
+.P
.in +4n
.EX
struct linux_dirent {
unsigned long d_ino; /* Inode number */
- unsigned long d_off; /* Offset to next \fIlinux_dirent\fP */
+ unsigned long d_off; /* Not an offset; see below */
unsigned short d_reclen; /* Length of this \fIlinux_dirent\fP */
char d_name[]; /* Filename (null\-terminated) */
/* length is actually (d_reclen \- 2 \-
@@ -80,18 +80,22 @@ struct linux_dirent {
}
.EE
.in
-.PP
+.P
.I d_ino
is an inode number.
.I d_off
-is the distance from the start of the directory to the start of the next
-.IR linux_dirent .
+is a filesystem-specific value with no specific meaning to user space,
+though on older filesystems it used to be
+the distance from the start of the directory to the start of the next
+.IR linux_dirent ;
+see
+.BR readdir (3) .
.I d_reclen
is the size of this entire
.IR linux_dirent .
.I d_name
is a null-terminated filename.
-.PP
+.P
.I d_type
is a byte at the end of the structure that indicates the file type.
It contains one of the following values (defined in
@@ -120,7 +124,7 @@ This is a UNIX domain socket.
.TP
.B DT_UNKNOWN
The file type is unknown.
-.PP
+.P
The
.I d_type
field is implemented since Linux 2.6.4.
@@ -130,7 +134,7 @@ structure.
Thus, on kernels up to and including Linux 2.6.3,
attempting to access this field always provides the value 0
.RB ( DT_UNKNOWN ).
-.PP
+.P
Currently,
.\" kernel 2.6.27
.\" The same sentence is in readdir.2
@@ -155,19 +159,19 @@ In addition,
supports an explicit
.I d_type
field.
-.PP
+.P
The
.BR getdents64 ()
system call is like
.BR getdents (),
except that its second argument is a pointer to a buffer containing
structures of the following type:
-.PP
+.P
.in +4n
.EX
struct linux_dirent64 {
ino64_t d_ino; /* 64\-bit inode number */
- off64_t d_off; /* 64\-bit offset to next structure */
+ off64_t d_off; /* Not an offset; see getdents() */
unsigned short d_reclen; /* Size of this dirent */
unsigned char d_type; /* File type */
char d_name[]; /* Filename (null\-terminated) */
@@ -217,11 +221,11 @@ In that case you will need to define the
or
.I linux_dirent64
structure yourself.
-.PP
+.P
Probably, you want to use
.BR readdir (3)
instead of these system calls.
-.PP
+.P
These calls supersede
.BR readdir (2).
.SH EXAMPLES
@@ -231,7 +235,7 @@ The program below demonstrates the use of
.BR getdents ().
The following output shows an example of what we see when running this
program on an ext2 directory:
-.PP
+.P
.in +4n
.EX
.RB "$" " ./a.out /testfs/"