当前位置:首页 » 操作系统 » c库源码

c库源码

发布时间: 2022-01-15 05:37:18

A. 如何查看c语言,内库的源代码

一般情况下是不能打开的。
除非使用反汇编软件。但是反汇编软件效果不尽如人意,需要人工猜测的地方太多!
而且如果使用了先进的代码模糊技术的话,基本上很难看透源代码的用意。
正常情况下,建议问作者索要源代码,如果作者的软件是闭源软件的话,如果不是大神并且时间不多,那么“打开exe格式的c语言文件的源代码”
基本上就是天方夜谭了。

B. C语言库函数源代码

http://www.gnu.org/software/libc/这里就有所有的c标准库函数源码

C. 如何看c语言标准库函数的源代码

1、首先标准只是规定了这些函数的接口和具体的运行效率的要求,这些函数具体是怎么写得要看各个编译器的实现和平台。

2、例如使用的编译器是visual studio,微软提供了一部分C运行时(CRT)的源码,里面会有memcpy,strcpy之类的函数的实现,在visual studio 2005下的路径是C:Program FilesMicrosoft Visual Studio 8VCcrtsrc。

D. 在哪里可以找到C语言标准库的实现源代码

linux下的glic库的源码链接:
http://ftp.gnu.org/gnu/glibc/,你可以下载最新版本的glibc-2.24.tar.gz这个压缩文件,在Windows系统下直接用WinRAR解压即可,如果在Linux系统下用命令行解压的话,命令如下:tar -xzvf glibc-2.24.tar.gz。

E. c库函数源码

不是你表达不清,也许只是你根本不想仔细看一睛VC下面目录的源码,事实上就是有的。后附其中的qsort.c,以证明所言不虚。

VC的库是提供源码的,这东西也不值钱。
X:\Program Files\Microsoft Visual Studio\VCXX\CRT\SRC
注意有些可能本身是用汇编写的。

/***
*qsort.c - quicksort algorithm; qsort() library function for sorting arrays
*
* Copyright (c) 1985-1997, Microsoft Corporation. All rights reserved.
*
*Purpose:
* To implement the qsort() routine for sorting arrays.
*
*******************************************************************************/

#include <cruntime.h>
#include <stdlib.h>
#include <search.h>

/* prototypes for local routines */
static void __cdecl shortsort(char *lo, char *hi, unsigned width,
int (__cdecl *comp)(const void *, const void *));
static void __cdecl swap(char *p, char *q, unsigned int width);

/* this parameter defines the cutoff between using quick sort and
insertion sort for arrays; arrays with lengths shorter or equal to the
below value use insertion sort */

#define CUTOFF 8 /* testing shows that this is good value */

/***
*qsort(base, num, wid, comp) - quicksort function for sorting arrays
*
*Purpose:
* quicksort the array of elements
* side effects: sorts in place
*
*Entry:
* char *base = pointer to base of array
* unsigned num = number of elements in the array
* unsigned width = width in bytes of each array element
* int (*comp)() = pointer to function returning analog of strcmp for
* strings, but supplied by user for comparing the array elements.
* it accepts 2 pointers to elements and returns neg if 1<2, 0 if
* 1=2, pos if 1>2.
*
*Exit:
* returns void
*
*Exceptions:
*
*******************************************************************************/

/* sort the array between lo and hi (inclusive) */

void __cdecl qsort (
void *base,
unsigned num,
unsigned width,
int (__cdecl *comp)(const void *, const void *)
)
{
char *lo, *hi; /* ends of sub-array currently sorting */
char *mid; /* points to middle of subarray */
char *loguy, *higuy; /* traveling pointers for partition step */
unsigned size; /* size of the sub-array */
char *lostk[30], *histk[30];
int stkptr; /* stack for saving sub-array to be processed */

/* Note: the number of stack entries required is no more than
1 + log2(size), so 30 is sufficient for any array */

if (num < 2 || width == 0)
return; /* nothing to do */

stkptr = 0; /* initialize stack */

lo = base;
hi = (char *)base + width * (num-1); /* initialize limits */

/* this entry point is for pseudo-recursion calling: setting
lo and hi and jumping to here is like recursion, but stkptr is
prserved, locals aren't, so we preserve stuff on the stack */
recurse:

size = (hi - lo) / width + 1; /* number of el's to sort */

/* below a certain size, it is faster to use a O(n^2) sorting method */
if (size <= CUTOFF) {
shortsort(lo, hi, width, comp);
}
else {
/* First we pick a partititioning element. The efficiency of the
algorithm demands that we find one that is approximately the
median of the values, but also that we select one fast. Using
the first one proces bad performace if the array is already
sorted, so we use the middle one, which would require a very
wierdly arranged array for worst case performance. Testing shows
that a median-of-three algorithm does not, in general, increase
performance. */

mid = lo + (size / 2) * width; /* find middle element */
swap(mid, lo, width); /* swap it to beginning of array */

/* We now wish to partition the array into three pieces, one
consisiting of elements <= partition element, one of elements
equal to the parition element, and one of element >= to it. This
is done below; comments indicate conditions established at every
step. */

loguy = lo;
higuy = hi + width;

/* Note that higuy decreases and loguy increases on every iteration,
so loop must terminate. */
for (;;) {
/* lo <= loguy < hi, lo < higuy <= hi + 1,
A[i] <= A[lo] for lo <= i <= loguy,
A[i] >= A[lo] for higuy <= i <= hi */

do {
loguy += width;
} while (loguy <= hi && comp(loguy, lo) <= 0);

/* lo < loguy <= hi+1, A[i] <= A[lo] for lo <= i < loguy,
either loguy > hi or A[loguy] > A[lo] */

do {
higuy -= width;
} while (higuy > lo && comp(higuy, lo) >= 0);

/* lo-1 <= higuy <= hi, A[i] >= A[lo] for higuy < i <= hi,
either higuy <= lo or A[higuy] < A[lo] */

if (higuy < loguy)
break;

/* if loguy > hi or higuy <= lo, then we would have exited, so
A[loguy] > A[lo], A[higuy] < A[lo],
loguy < hi, highy > lo */

swap(loguy, higuy, width);

/* A[loguy] < A[lo], A[higuy] > A[lo]; so condition at top
of loop is re-established */
}

/* A[i] >= A[lo] for higuy < i <= hi,
A[i] <= A[lo] for lo <= i < loguy,
higuy < loguy, lo <= higuy <= hi
implying:
A[i] >= A[lo] for loguy <= i <= hi,
A[i] <= A[lo] for lo <= i <= higuy,
A[i] = A[lo] for higuy < i < loguy */

swap(lo, higuy, width); /* put partition element in place */

/* OK, now we have the following:
A[i] >= A[higuy] for loguy <= i <= hi,
A[i] <= A[higuy] for lo <= i < higuy
A[i] = A[lo] for higuy <= i < loguy */

/* We've finished the partition, now we want to sort the subarrays
[lo, higuy-1] and [loguy, hi].
We do the smaller one first to minimize stack usage.
We only sort arrays of length 2 or more.*/

if ( higuy - 1 - lo >= hi - loguy ) {
if (lo + width < higuy) {
lostk[stkptr] = lo;
histk[stkptr] = higuy - width;
++stkptr;
} /* save big recursion for later */

if (loguy < hi) {
lo = loguy;
goto recurse; /* do small recursion */
}
}
else {
if (loguy < hi) {
lostk[stkptr] = loguy;
histk[stkptr] = hi;
++stkptr; /* save big recursion for later */
}

if (lo + width < higuy) {
hi = higuy - width;
goto recurse; /* do small recursion */
}
}
}

/* We have sorted the array, except for any pending sorts on the stack.
Check if there are any, and do them. */

--stkptr;
if (stkptr >= 0) {
lo = lostk[stkptr];
hi = histk[stkptr];
goto recurse; /* pop subarray from stack */
}
else
return; /* all subarrays done */
}

/***
*shortsort(hi, lo, width, comp) - insertion sort for sorting short arrays
*
*Purpose:
* sorts the sub-array of elements between lo and hi (inclusive)
* side effects: sorts in place
* assumes that lo < hi
*
*Entry:
* char *lo = pointer to low element to sort
* char *hi = pointer to high element to sort
* unsigned width = width in bytes of each array element
* int (*comp)() = pointer to function returning analog of strcmp for
* strings, but supplied by user for comparing the array elements.
* it accepts 2 pointers to elements and returns neg if 1<2, 0 if
* 1=2, pos if 1>2.
*
*Exit:
* returns void
*
*Exceptions:
*
*******************************************************************************/

static void __cdecl shortsort (
char *lo,
char *hi,
unsigned width,
int (__cdecl *comp)(const void *, const void *)
)
{
char *p, *max;

/* Note: in assertions below, i and j are alway inside original bound of
array to sort. */

while (hi > lo) {
/* A[i] <= A[j] for i <= j, j > hi */
max = lo;
for (p = lo+width; p <= hi; p += width) {
/* A[i] <= A[max] for lo <= i < p */
if (comp(p, max) > 0) {
max = p;
}
/* A[i] <= A[max] for lo <= i <= p */
}

/* A[i] <= A[max] for lo <= i <= hi */

swap(max, hi, width);

/* A[i] <= A[hi] for i <= hi, so A[i] <= A[j] for i <= j, j >= hi */

hi -= width;

/* A[i] <= A[j] for i <= j, j > hi, loop top condition established */
}
/* A[i] <= A[j] for i <= j, j > lo, which implies A[i] <= A[j] for i < j,
so array is sorted */
}

/***
*swap(a, b, width) - swap two elements
*
*Purpose:
* swaps the two array elements of size width
*
*Entry:
* char *a, *b = pointer to two elements to swap
* unsigned width = width in bytes of each array element
*
*Exit:
* returns void
*
*Exceptions:
*
*******************************************************************************/

static void __cdecl swap (
char *a,
char *b,
unsigned width
)
{
char tmp;

if ( a != b )
/* Do the swap one character at a time to avoid potential alignment
problems. */
while ( width-- ) {
tmp = *a;
*a++ = *b;
*b++ = tmp;
}
}

F. 求C语言中的库函数的源代码 如printf()函数,我要它的源代码

在stdio.h中。如果是数学函数如sin()等的,在math.h中。而string类的函数则在string.h中。自己看吧

G. 完整的C++库函数源代码哪里有下载

c库函数源代码
http://dsa7.fileflyer.com/d/427f1cec-63eb-4c6b-b7ac-da7c28595a8e/w44z/5SeIzB5/13898388clibsource.rar

H. linux下怎么查看c函数库的源代码

头文件在/usr/include/sys/time.h

如果要看定义,下载glibc的源代码。

I. 谁能提供C语言stdio库函数源代码

http://mirrors.kernel.org/gnu/glibc/glibc-2.7.tar.gz
下载Linux的C语言标准库,它包含stdio.h等等

J. c标准库中的源码实现细节需要看懂吗

库函数的实现细节源码不需要完全看的东,作为一个程序员,首先需要掌握的是库函数的功能、语法和用法。
至于库函数的实现细节,可等有了基础之后再去搞明白就可以了。搞明白哪些对自己的编程也是很有帮助的。

热点内容
安卓手机什么是双卡 发布:2024-12-25 23:54:40 浏览:892
dnd服务器ip地址 发布:2024-12-25 23:48:08 浏览:196
cad解压没有 发布:2024-12-25 23:48:03 浏览:14
超星做题脚本 发布:2024-12-25 23:35:14 浏览:908
打开加密pdf 发布:2024-12-25 23:24:57 浏览:742
动态sql查询条件 发布:2024-12-25 23:24:56 浏览:303
qq群上传速度 发布:2024-12-25 23:13:09 浏览:480
编程工程学 发布:2024-12-25 23:07:28 浏览:717
李小璐贾乃亮超级访问 发布:2024-12-25 22:47:50 浏览:719
电信精品宽带多ip路由如何配置 发布:2024-12-25 22:45:44 浏览:384