能找到cp的源代码吗？

wuqingabc · 发表于 2004-2-11 22:46:09

能在内核中找到实现拷贝命令cp的c语言源代码吗？能的话告诉我在linux中哪个文件夹，谢谢啦

qing · 发表于 2004-2-11 22:49:15

在lfs.linuxsir.cn查看。。

wuqingabc · 发表于 2004-2-12 09:16:14

搜了cp没有搜到……内核中没有源代码吗？难道只有已经编译的了吗？
哪位大侠能不能帮我找一下呀？

qing · 发表于 2004-2-12 09:57:31

最初由 wuqingabc 发表
搜了cp没有搜到……内核中没有源代码吗？难道只有已经编译的了吗？
哪位大侠能不能帮我找一下呀？

看cp来自哪个软件包。。ok

wuqingabc · 发表于 2004-2-12 10:59:16

我是新手，能不能具体说说呀，谢谢你啦版主

qing · 发表于 2004-2-12 11:10:37

http://lfs.linuxsir.cn/htdocs/lfscvs/appendixa/coreutils.html

qing · 发表于 2004-2-12 11:43:37

man cp

fileutils-4.1

qing · 发表于 2004-2-12 11:48:59

http://freebsd.ntu.edu.tw/bsd/5/19/53.html

◇ [hack] File system
發信人: [email]Thinker@freebsd.ee.ntu.edu.tw[/email] (Thinker), 看板: BSD
標題: [hack] File system
發信站: ?牧汩_始 (Thu Feb 5 20:08:49 1998)
轉信站: Maxwell!bbs.ee.ntu!freebsd.ntu!fromzero
TITLE: File system
KEYWORDS: [file] [vnode] [mount] [file system] [fileops] [vfsops]
[vnodeop_desc] [vnodeopv_entry_desc] [vnodeopv_desc]
[descriptor table]
ABSTRACT:
本文討論關於 file system 部分, 就紅皮書未說明清楚的部分
加以補?. 紅皮書是研究 4.4BSD 者不可或缺的指引書籍, 但
?際 implement 的一些細?, 在紅皮書裏?K沒有清楚交代.
因此在?際 trace source 時, 會有一些失落的環?不易了解.
本文就這些環?進行補?, 以便利新進之 hacker 們, 能在紅
皮書和程式碼之間做個連結.
＊紅皮書: The Design and Implementation of the 4.4BSD Operating System,
Addison Wesley.
file:
process 是透過 file descriptor access 檔案, 其過程為
＊詳見紅皮書 section 6.4 & fingure 6.4
其中 file table 是 kernel global variable, 不屬於
任何一個 process. 4.4BSD 提供檔案系統和多種的 IPC
系統, file 則是做為這些不同系統的共同介面. process 只要
透過 file 介面, 就可以使用相的方法和程式碼處理檔案, socket
和 pipe, 三種不同的系統. file 是一個物件化的介面, 提供
一個 generic 的 structure 和 functions. 這些 function
被稱為 operator, 以 pointer 的形式記錄在 operator table 裏
, file.f_ops (type: &quotfileops *") 則指向 operator table. 檔案
系統和 socket 和 pipe 系統提供各自的 operator table, 再由
file.f_ops 選擇合適的 table. 如: socket 的 file.f_ops 則
指向 socket 的 operator table.
+-
file system
------ -------------------------
*f_ops pipeops (pipe)
socketops (socket)
vnops (vfs)
*f_data vnode (vfs)
socket (socket)
pipe (pipe)
＊ pipeops, socketops, vnops 是 global variables, 分別屬於
pipe, socket, vfs 等三個 domain. 這三個 domain 都是透過
file 介面存取, 而不同的 domain 對 file 所定義取介面有不
同的解譯和處理. 依 domain 的不同, f_ops (type 是 fileops*)
指向不同 domain 所定義的 operator list. kernel 透過
operator list, 以 indirect function 方式, 呼叫對映功能的
function. (vfs: virtual file system)
＊ f_data 依 domain 的不同而指向不同的 structure. 在 vfs
domain 是 vnode, 在 socket domain 則是 socket 結構, 在
pipe domain 裏, 則是 pipe 結構. kernel 使用這些 sturcture
紀錄一些相關資?.
+-
Vnode:
在 BSD 提供/支援多種不同的 file system, 如 ufs, nfs, procfs
... etc, kernel 使用 vfs 統合這些不同的 file system, 提供物
件化的介面, 隱藏 file system 之間的差?. vnode 在 vfs 裏扮
演著一個重要的角色. ＊詳見紅皮書 Sectin 6.5
vnode 裏 member, v_op 的 type 為 "(vop_t **)", vop_t 的定義:
+-
typedef int vop_t __P((void *));
+-
這定義了一個標準的介面. v_op 指向一個己定義好的 list, list
中每一個 element 都指向代表特定功能的 function (list 中每個
位置所代表的意義都已預定了), 這些 function 稱之為 operator.
每個 file system 都提供自己的 operator, 所自己的 list. 不同
file system, 則其 vnode 內的 v_op 指向 file system 所提供的
operator's list. operator 的第一個也是唯一的一個 argument
的 type 為 "(void *)", 這代表可以傳入任何 type 的 ptr. 事?
上, 代表特定意義的 operator, 其 argument 的 type 有特定的
type. 如, VOP_CREATE 的 argument 的 type:
+-
struct vop_create_args {
struct vnodeop_desc *a_desc;
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
};
+-
不論任何一種 file system, 代表 VOP_CREATE 這個功能的
operator, 它的 argument 都為這個 type. vfs 的 vnops 即是?
file 的 f_data 取得 vnode, 再透過 vnode 呼叫這些 operator, 完
成其功能.
+-
-> file -> vnode -> operator list -> operator
+-
Mount:
在 UNIX 系統中, 任何 file system 都必需事先 mount 在 mount point
才能被系統使用. 4.4BSD 在 kernel 裏以 struct mount 表示所有的
mount point. ＊詳見紅皮書 section 6.5 和 Fingure 6.7.
mount.mnt_op 其 type 為 (struct vfsops *), 定義一些針對整個 file
system 而非個別檔案的 operator, 如 vfs_mount, vfs_unmout, vfs_sync
... etc.
初始化:
vfs 的 initial code 是 kern/vfs_init.c 裏的 vfsubut(),
file system 的 root 則是由 kern/vfs_conf.c 裏的 vfs_mountroot().
附 1:
+-
/*
* Kernel descriptor table.
* One entry for each open kernel vnode and socket.
*/
struct file {
LIST_ENTRY(file) f_list;/* list of active files */
short f_flag; /* see fcntl.h */
#define DTYPE_VNODE 1 /* file */
#define DTYPE_SOCKET 2 /* communications endpoint */
#define DTYPE_PIPE 3 /* pipe */
#define DTYPE_FIFO 4 /* fifo (named pipe) */
short f_type; /* descriptor type */
short f_count; /* reference count */
short f_msgcount; /* references from message queue */
struct ucred *f_cred; /* credentials associated with descriptor */
struct fileops {
int (*fo_read) __P((struct file *fp, struct uio *uio,
struct ucred *cred));
int (*fo_write) __P((struct file *fp, struct uio *uio,
struct ucred *cred));
int (*fo_ioctl) __P((struct file *fp, int com,
caddr_t data, struct proc *p));
int (*fo_select) __P((struct file *fp, int which,
struct proc *p));
int (*fo_close) __P((struct file *fp, struct proc *p));
} *f_ops;
off_t f_offset;
caddr_t f_data; /* vnode or socket */
};
/*
* Structure per mounted file system. Each mounted file system has an
* array of operations and an instance record. The file systems are
* put on a doubly linked list.
*/
struct mount {
CIRCLEQ_ENTRY(mount) mnt_list; /* mount list */
struct vfsops *mnt_op; /* operations on fs */
struct vfsconf *mnt_vfc; /* configuration info */
struct vnode *mnt_vnodecovered; /* vnode we mounted on */
struct vnodelst mnt_vnodelist; /* list of vnodes this mount */
int mnt_flag; /* flags */
int mnt_maxsymlinklen; /* max size of short symlink */
struct statfs mnt_stat; /* cache of filesystem stats */
qaddr_t mnt_data; /* private data */
/* struct vfsconf *mnt_vfc; */ /* configuration info */
time_t mnt_time; /* last time written*/
};
/*
* used to get configured filesystems information
*/
#define VFS_MAXNAMELEN 32
struct vfsconf {
void *vfc_vfsops;
char vfc_name[VFS_MAXNAMELEN];
int vfc_index;
int vfc_refcount;
int vfc_flags;
};
struct vfsops {
int (*vfs_mount) __P((struct mount *mp, char *path, caddr_t data,
struct nameidata *ndp, struct proc *p));
int (*vfs_start) __P((struct mount *mp, int flags,
struct proc *p));
int (*vfs_unmount) __P((struct mount *mp, int mntflags,
struct proc *p));
int (*vfs_root) __P((struct mount *mp, struct vnode **vpp));
int (*vfs_quotactl) __P((struct mount *mp, int cmds, uid_t uid,
caddr_t arg, struct proc *p));
int (*vfs_statfs) __P((struct mount *mp, struct statfs *sbp,
struct proc *p));
int (*vfs_sync) __P((struct mount *mp, int waitfor,
struct ucred *cred, struct proc *p));
int (*vfs_vget) __P((struct mount *mp, ino_t ino,
struct vnode **vpp));
int (*vfs_fhtovp) __P((struct mount *mp, struct fid *fhp,
struct mbuf *nam, struct vnode **vpp,
int *exflagsp, struct ucred **credanonp));
int (*vfs_vptofh) __P((struct vnode *vp, struct fid *fhp));
int (*vfs_init) __P((void));
};
struct vnode {
u_long v_flag; /* vnode flags (see below) */
int v_writecount; /* reference count of writers */
int v_holdcnt; /* page & buffer references */
daddr_t v_lastr; /* last read (read-ahead) */
u_long v_id; /* capability identifier */
struct mount *v_mount; /* ptr to vfs we are in */
vop_t **v_op; /* vnode operations vector */
TAILQ_ENTRY(vnode) v_freelist; /* vnode freelist */
LIST_ENTRY(vnode) v_mntvnodes; /* vnodes for mount point */
struct buflists v_cleanblkhd; /* clean blocklist head */
struct buflists v_dirtyblkhd; /* dirty blocklist head */
long v_numoutput; /* num of writes in progress */
enum vtype v_type; /* vnode type */
union {
struct mount *vu_mountedhere;/* ptr to mounted vfs (VDIR) */
struct socket *vu_socket; /* unix ipc (VSOCK) */
struct specinfo *vu_specinfo; /* device (VCHR, VBLK) */
struct fifoinfo *vu_fifoinfo; /* fifo (VFIFO) */
struct fifoinfo *vu_fifoinfo; /* fifo (VFIFO) */
} v_un;
struct nqlease *v_lease; /* Soft reference to lease */
daddr_t v_lastw; /* last write (write cluster) */
daddr_t v_cstart; /* start block of cluster */
daddr_t v_lasta; /* last allocation */
int v_clen; /* length of current cluster */
int v_ralen; /* Read-ahead length */
int v_usage; /* Vnode usage counter */
daddr_t v_maxra; /* last readahead block */
struct vm_object *v_object; /* Place to store VM object */
enum vtagtype v_tag; /* type of underlying data */
void *v_data; /* private data for fs */
};
struct vnodeop_desc {
int vdesc_offset; /* offset in vector--first for speed */
char *vdesc_name; /* a readable name for debugging */
int vdesc_flags; /* VDESC_* flags */
/*
* These ops are used by bypass routines to map and locate arguments.
* Creds and procs are not needed in bypass routines, but sometimes
* they are useful to (for example) transport layers.
* Nameidata is useful because it has a cred in it.
*/
int *vdesc_vp_offsets; /* list ended by VDESC_NO_OFFSET */
int vdesc_vpp_offset; /* return vpp location */
int vdesc_cred_offset; /* cred location, if any */
int vdesc_proc_offset; /* proc location, if any */
int vdesc_componentname_offset; /* if any */
/*
* Finally, we've got a list of private data (about each operation)
* for each transport layer. (Support to manage this list is not
* yet part of BSD.)
*/
caddr_t *vdesc_transports;
};
/*
* This structure is used to configure the new vnodeops vector.
*/
struct vnodeopv_entry_desc {
struct vnodeop_desc *opve_op; /* which operation this is */
vop_t *opve_impl; /* code implementing this operation */
};
struct vnodeopv_desc {
/* ptr to the ptr to the vector where op should go */
vop_t ***opv_desc_vector_p;
struct vnodeopv_entry_desc *opv_desc_ops; /* null terminated list */
};
+-
-----------------------------------------------------------------------------
沒事請叫我 Thinker, thx! Thinker
[email]Thinker.bbs@yzit.edu.tw[/email]
[email]Thinker@freebsd.ee.ntu.edu.tw[/email]
Origin: ?牧汩_始 freebsd.ee.ntu.edu.tw (140.112.19.123)

复制代码

qing · 发表于 2004-2-12 12:00:11

http://www.win.tue.nl/~aeb/linux/vfs/trail-3.html

qing · 发表于 2004-2-12 12:05:39

/*
Simple file copy program using sendfile(2).
usage: fastcp <source> <destination>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/sendfile.h>
#include <sys/stat.h>
int main (int argc, char** argv)
{
int src; /* file descriptor for source file */
int dest; /* file descriptor for destination file */
struct stat stat_buf; /* hold information about input file */
off_t offset = 0; /* byte offset used by sendfile */
int rc; /* return code from sendfile */
/* check for two command line arguments */
if (argc != 3) {
fprintf(stderr, "usage: %s <source> <destination>\n", argv[0]);
exit(1);
}
/* check that source file exists and can be opened */
src = open(argv[1], O_RDONLY);
if (src == -1) {
fprintf(stderr, "unable to open '%s': %s\n", argv[1], strerror(errno));
exit(1);
}
/* get size and permissions of the source file */
fstat(src, &stat_buf);
/* open destination file */
dest = open(argv[2], O_WRONLY|O_CREAT, stat_buf.st_mode);
if (dest == -1) {
fprintf(stderr, "unable to open '%s': %s\n", argv[2], strerror(errno));
exit(1);
}
/* copy file using sendfile */
rc = sendfile (dest, src, &offset, stat_buf.st_size);
if (rc == -1) {
fprintf(stderr, "error from sendfile: %s\n", strerror(errno));
exit(1);
}
if (rc != stat_buf.st_size) {
fprintf(stderr, "incomplete transfer from sendfile: %d of %d bytes\n",
rc,
(int)stat_buf.st_size);
exit(1);
}
/* clean up and exit */
close(dest);
close(src);
return 0;
}

复制代码

http://www.linuxgazette.com/issue91/misc/tranter/fastcp.c.txt

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