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我正在查看 Linux 指南中函数 int brk() 的文档：

SYNOPSIS
   #include <unistd.h>

   int brk(void *addr);

   void *sbrk(intptr_t increment);



Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

   brk(), sbrk():
       Since glibc 2.19:
           _DEFAULT_SOURCE ||
               (_XOPEN_SOURCE >= 500) &&
               ! (_POSIX_C_SOURCE >= 200112L)
       From glibc 2.12 to 2.19:
           _BSD_SOURCE || _SVID_SOURCE ||
               (_XOPEN_SOURCE >= 500) &&
               ! (_POSIX_C_SOURCE >= 200112L)
       Before glibc 2.12:
           _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500

DESCRIPTION      
       brk() and sbrk() change the location of the program break, which
       defines the end of the process's data segment (i.e., the program
       break is the first location after the end of the uninitialized data
       segment).  Increasing the program break has the effect of allocating
       memory to the process; decreasing the break deallocates memory.

   brk() sets the end of the data segment to the value specified by
   addr, when that value is reasonable, the system has enough memory,
   and the process does not exceed its maximum data size (see
   setrlimit(2)).

RETURN VALUE    
       On success, brk() returns zero.  On error, -1 is returned, and errno
       is set to ENOMEM.

还有一些我不明白的地方：如果 brk() 只将数据段的末尾设置为 addr 指定的值，那么为什么它的参数是 void* 而不是 int 类型？

谢谢您的帮助！

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1 回答 1

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我想，由于“中断是数据区域当前末尾之外的第一个位置的地址”（维基百科），你不能也不应该知道那里有什么数据，因此指针不能是除了 void 之外的任何其他类型。

于 2020-01-11T15:09:24.367 回答