acct【acct】acct -- 启用/禁止进程信息记录功能
公司简介介绍/* 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/ormodify it under the terms of thversion 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 ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNULesser General Public License for more details.You should have received a copy of the GNU Lesser General PublicLicense along with the GNU C Library; if not, write to the FreeSoftware Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA02111-1307 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 16comp_t is a 16-bit "floating" point number with a 3-bit base 8exponent and a 13-bit fraction. See linux/kernel/acct.c for thespecific encoding system used.typedef u_int16_t comp_t;struct acctchar 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的频率（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:有错误时返回-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的符号连结[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写操作[ETXTBSY] 试图对执行中的档案请求写操作[EFAULT] file参数指向的地址超出了进程的存取空间[EIO] 读/写档案系统时遇到了I/O错误历史: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）