知道确切的字符串数组长度 [英] knowing exact string array length ?
问题描述
您好。我是C语言的新手。我有一个包含许多字符的二进制文件
定义为50个字符的数组
字符数组[50]
但在某些情况下，这50个字符中的许多字符都没有被使用。我想知道我怎么知道每个阵列中有多少个字符真的是
？
谢谢
Alberto
Hi. Im newbie in C language. I have a binary file with many character
arrays of 50 character defined as
char array[50]
But in some cases, many of these 50 characters are not being used. I
would like to know how could I know how many characters are really being
used in each array ?
Thanks
Alberto
推荐答案
alberto写道：
alberto wrote:
嗨。我是C语言的新手。我有一个包含许多字符的二进制文件，其中包含50个字符的数组，定义为
char数组[50]
但在某些情况下，这50个字符中的许多都是没被使用。我想知道我怎么知道每个阵列中确实使用了多少个字符？
Hi. Im newbie in C language. I have a binary file with many character
arrays of 50 character defined as
char array[50]
But in some cases, many of these 50 characters are not being used. I
would like to know how could I know how many characters are really being
used in each array ?
你用什么意思使用？你的意思是他们不是零吗？
以下将给你一个计数，其中有多少首字符
非零。
#include< stdlib.h>
#include< stdio.h>
#include< string.h>
#define BLOCK_SIZE 50
int
main（无效）
{
char buf [BLOCK_SIZE + 1];
int count = 0;
buf [BLOCK_SIZE] = 0;
而（fread（buf，sizeof * buf，BLOCK_SIZE，stdin）== BLOCK_SIZE）
printf（" Block％d used％d bytes \ n"，++ count，
strlen（buf））;
}
What do you mean by "used"? Do you mean that they are non-zero?
The following will give you a count of how many of the first characters
are non-zero.
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define BLOCK_SIZE 50
int
main(void)
{
char buf[BLOCK_SIZE+1];
int count=0;
buf[BLOCK_SIZE] = 0;
while(fread(buf, sizeof *buf, BLOCK_SIZE, stdin) == BLOCK_SIZE)
printf("Block %d used %d bytes\n", ++count,
strlen(buf));
}
alberto< a@a.com>写道：
alberto <a@a.com> writes:
嗨。我是C语言的新手。我有一个包含许多字符的二进制文件，其中包含50个字符的数组，定义为
char数组[50]
但在某些情况下，这50个字符中的许多都是没被使用。我想知道我怎么知道在每个阵列中使用了多少个字符？
Hi. Im newbie in C language. I have a binary file with many character
arrays of 50 character defined as
char array[50]
But in some cases, many of these 50 characters are not being used. I
would like to know how could I know how many characters are really
being used in each array ?
如果你可以定义你的内容意思是用过，答案很明显。
如果你不能，那就没有答案。
-
Keith Thompson（The_Other_Keith） ks***@mib.org < http://www.ghoti.net / ~kst>
圣地亚哥超级计算机中心< *> < http://users.sdsc.edu/~kst>
我们必须做点什么。这是事情。因此，我们必须这样做。
If you can define what you mean by "used", the answer will be obvious.
If you can''t, there is no answer.
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
BillPursellescribió：
Bill Pursell escribió:
alberto写道：
alberto wrote:
嗨。我是C语言的新手。我有一个包含许多字符的二进制文件，其中包含50个字符的数组，定义为
char数组[50]
但在某些情况下，这50个字符中的许多都是没被使用。我想知道我怎么知道每个阵列中确实使用了多少个字符？
Hi. Im newbie in C language. I have a binary file with many character
arrays of 50 character defined as
char array[50]
But in some cases, many of these 50 characters are not being used. I
would like to know how could I know how many characters are really being
used in each array ?
你用什么意思使用？你的意思是他们不是零吗？
以下内容将为你计算出第一个角色中有多少是非零的。
#include< stdlib .h>
#include< stdio.h>
#include< string.h>
#define BLOCK_SIZE 50
int
main（ void）
{char buf [BLOCK_SIZE + 1];
int count = 0;
buf [BLOCK_SIZE] = 0;
while（fread （buf，sizeof * buf，BLOCK_SIZE，stdin）== BLOCK_SIZE）
printf（" Block％d used％d bytes \\\
"，++ count，
strlen（buf））;
}
What do you mean by "used"? Do you mean that they are non-zero?
The following will give you a count of how many of the first characters
are non-zero.
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define BLOCK_SIZE 50
int
main(void)
{
char buf[BLOCK_SIZE+1];
int count=0;
buf[BLOCK_SIZE] = 0;
while(fread(buf, sizeof *buf, BLOCK_SIZE, stdin) == BLOCK_SIZE)
printf("Block %d used %d bytes\n", ++count,
strlen(buf));
}
tnbx为您的答案。是的，我的意思是，如果我有阵列
char buf [50]
那么有时它将包含20个字符而不是'' \'''我想知道
这些字符的数量，因为我想用指针做一个链接的动态
列表，每个节点应该有串QUOT; 50个字符的静态
数组，真正的字符不是''\0''，所以我必须知道
数字，之后使用calloc或malloc函数
tnbx for your answer. Yes, I mean that if I have the array
char buf[50]
then some times it will contain 20 characters not ''\0'' I want to know
the amount of these characters, because I want to do a linked dynamic
list with pointers and each node should have the "string" of the static
array of 50 chars with really characters not ''\0'', so I must know the
number and after that use calloc or malloc functions
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