/* * controlflow.c * * "if" processing is done with two state variables * if_state and if_result */ #include <stdio.h> #include "smsh.h" enum states {NEUTRAL, WANT_THEN, THEN_BLOCK}; enum results {SUCESS, FAIL};
但要注意的是,system可能会引起一个权限的传递。比如,program1有在root权限下设置的set-user-ID,这就意味着任何用户在执行program1时都会具有superuser permission.那么,如果在program1中调用system("program2"),就会将program1的superuser permission传递给program2,而这显然是我们不愿意看到的。 三.我看书时的一些笔...
---Commonfiles ofFS--- type.h :EXT2 data structure typesglobal.c :globalvariables ofFSutil.c :commonutility functions:getino(),iget(),iput(),search(),etc.allocate_deallocate.c:inodes/blocks management functions --- 第1级别实现了基本文件系统树。它包含以下文件,实现了指定函数。 ---Level-1o...
Data mining UNIX system performance data to identify predictor variables for use in multivariate regression equations that forecast CPU consumptionThe enormous popularity and concomitant profitability of the rapidly evolving internet based "business-to business" (B2B) model is fundamentally altering the ...
regardless of what platform it happened to be on. There were minor differences that were easily handled by doing what one should always do when writing robust and well-planned scripts: we had a central function library, used variables rather than hardcoded locations, and included solid error hand...
109 Displaying currently defined variables...110 Using positional parameters — the $N construct...110 Using quotation marks to enclose a construct in a shell script...
Review Request: python-expandvars - Expand system variables Unix style Keywords: Status:CLOSED ERRATA Alias:None Product:Fedora Component:Package Review Version:rawhide Hardware:All OS:Linux Priority:medium Severity:medium Target Milestone:--- Assignee:Maxwell G...
在POSIX标准中定义了三种线程同步机制: Mutexes(互斥量), Condition Variables(条件变量)和POSIX Semaphores(信号量) 。NPTL基本上实现了POSIX,而glibc又使用NPTL作为自己的线程库。因此glibc中包含了这三种同步机制 的实现(当然还包括其他的同步机制,如APUE里提到的读写锁)。 Glibc中常用的线程同步方式举例: Semaphore...
Computer information Logging system messagesEnvironment VariablesAn environment block is a block of memory allocated within the process address space. Each block contains a set of name value pairs. All UNIX variants support process environment blocks. The particular differences between Interix and other ...
Resets the high-water mark for a system limit to 0. SER Reports serialization for all in-use, shared memory mutexes (mutual exclusion locks) and condition variables. Each mutex and condition variable is identified by the shared memory ID and the location of the shared memory object. If the...