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48 lines
1.2 KiB
HTML
48 lines
1.2 KiB
HTML
<h1>动态内存 - realloc</h1>
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<p>原型：extern void *realloc(void *mem_address, unsigned int newsize);</p>
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<p>用法：#include <alloc.h></p>
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<p>功能：改变mem_address所指内存区域的大小为newsize长度。</p>
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<p>说明：如果重新分配成功则返回指向被分配内存的指针，否则返回空指针NULL。</p>
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当内存不再使用时，应使用free()函数将内存块释放。
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举例：<pre><code class="language-c">
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// realloc.c
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#include <syslib.h>
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#include <alloc.h>
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main()
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{
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char *p;
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clrscr(); // clear screen
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p=(char *)malloc(100);
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if(p)
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printf("Memory Allocated at: %x",p);
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else
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printf("Not Enough Memory!\n");
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getchar();
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p=(char *)realloc(p,256);
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if(p)
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printf("Memory Reallocated at: %x",p);
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else
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printf("Not Enough Memory!\n");
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free(p);
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getchar();
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return 0;
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}
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</code></pre>相关函数：<a href="calloc.html">calloc</a>,<a href="free.html">free</a>,<a href="malloc.html">malloc</a>
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