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acct

acct

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介绍

/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of th
version 2.1 of the License, or (at your option) any later version.
The GNU C Library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */

详细

#ifndef _SYS_ACCT_H
#define _SYS_ACCT_H 1
#include <features.h>
#define __need_time_t
#include <time.h>
#include <sys/types.h>
__BEGIN_DECLS
#define ACCT_COMM 16
comp_t is a 16-bit "floating" point number with a 3-bit base 8
exponent and a 13-bit fraction. See linux/kernel/acct.c for the
specific encoding system used.
typedef u_int16_t comp_t;
struct acct
char ac_flag; /* Accounting flags. */
u_int16_t ac_uid; /* Accounting user ID. */
u_int16_t ac_gid; /* Accounting group ID. */
u_int16_t ac_tty; /* Controlling tty. */
u_int32_t ac_btime; /* Beginning time. */
comp_t ac_utime; /* Accounting user time. */
comp_t ac_stime; /* Accounting system time. */
comp_t ac_etime; /* Accounting elapsed time. */
comp_t ac_mem; /* Accounting average memory usage. */
comp_t ac_io; /* Accounting chars transferred. */
comp_t ac_rw; /* Accounting blocks read or written. */
comp_t ac_minflt; /* Accounting minor pagefaults. */
comp_t ac_majflt; /* Accounting major pagefaults. */
comp_t ac_swaps; /* Accounting number of swaps. */
u_int32_t ac_exitcode; /* Accounting process exitcode. */
char ac_comm[ACCT_COMM+1]; /* Accounting command name. */
char ac_pad[10]; /* Accounting padding bytes. */
};
enum
{
AFORK = 0x01, /* Has executed fork, but no exec. */
ASU = 0x02, /* Used super-user privileges. */
ACORE = 0x08, /* Dumped core. */
AXSIG = 0x10 /* Killed by a signal. */
};
#define AHZ 100
/* Switch process accounting on and off. */
extern int acct (__const char *__filename) __THROW;
__END_DECLS
#endif /* sys/acct.h */

文库:

Standard C Library (libc, -lc)

概要:

#include <unistd.h>
int acct(const char * file, int mode);

详述:

acct()系统调用禁止/启用系统记录进程信息。若file为NULL,记录功能将被禁用;
若file指向一个存在的档案(以'\0'结尾),则记录功能被启用,
正常结束的进程都会在该档案尾添加对应的信息。异常结束是指重启或其它致命的系统问题
acct()不能生成那些永远不会结束的进程的信息。
关于acct()使用的记录结构及其它相关信息,请参阅<sys/acct.h>及acct(5)。
该系统调用只能由超级用户使用。

笔记:

当记录档案所在的档案系统空间已满时,记录功能将被自动禁用;当空间足够时,
它会被自动启用。自动行为可以通过sysctl(8)修改对应的变数来控制
kern.acct_chkfreq 指定检查剩余空间大小频率(秒)
kern.acct_resume 剩余空间高于该百分比时,将恢复记录功能
kern.acct_suspend 剩余空间低于该百分比时,将暂停记录功能

返回值:

错误时返回-1。file档案必须存在且只能由超级用户调用。

错误:

acct()失败时将设定errno为下列错误常量:
[EPERM] 调用者不是超级用户
[ENOTDIR] file中的某目录组分不是目录
[ENAMETOOLONG] file中的某目录组分超过255位元组或file超过1023位元组
[ENOENT] 档案不存在
[ELOOP] 转换路径时遇到了太多符号连结
[EACCES] file中某目录组分不允许搜寻或file不是一个普通档案
[EROFS] 试图在唯读档案系统上请求操作
[ETXTBSY] 试图对执行中的档案请求写操作
[EFAULT] file参数指向的地址出了进程的存取空间
[EIO] 读/写档案系统时遇到了I/O错误
acct()系统调用在AT&T UNIX版本7里首次出现。
(2)ACCT :ACCOUNT 帐目,帐户 (在外贸中常用到这个缩写

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