C语言 如何从C中的字符串中删除回车符？
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How to remove a carriage return from a string in C?
提问by syedmuhd
Possible Duplicate:
Remove characters from a string in C
可能的重复：
从 C 中的字符串中删除字符
Do you have an example of C code to remove carriage returns in a string?
您是否有删除字符串中回车符的 C 代码示例？
回答by paxdiablo
The simplest solution is to probably just process the string character by character, with pointers for source and destination:
最简单的解决方案可能只是逐个字符地处理字符串，并使用指向源和目标的指针：
#include <stdio.h>
#include <string.h>
int main (void) {
char str[] = "This is a two-line\r\nstring with DOS line endings.\r\n";
printf("%d [%s]\n",strlen(str), str);
// ========================
// Relevant code in this section.
char *src, *dst;
for (src = dst = str; *src != '51 [This is a two-line
string with DOS line endings.
]
49 [This is a two-line
string with DOS line endings.
]
'; src++) {
*dst = *src;
if (*dst != '\r') dst++;
}
*dst = '#include <stdio.h>
#include <stdlib.h>
#include <string.h>
void remove_char_from_string(char c, char *str)
{
int i=0;
int len = strlen(str)+1;
for(i=0; i<len; i++)
{
if(str[i] == c)
{
// Move all the char following the char "c" by one to the left.
strncpy(&str[i],&str[i+1],len-i);
}
}
}
void replace_char_from_string(char from, char to, char *str)
{
int i = 0;
int len = strlen(str)+1;
for(i=0; i<len; i++)
{
if(str[i] == from)
{
str[i] = to;
}
}
}
int main(void) {
char *original = "a\nmultiline\nstring";
int original_len = strlen(original)+1;
char *string = (char *)malloc(original_len);
memset(string,0,original_len);
strncpy(string,original,original_len);
replace_char_from_string('\n',' ',string);
printf("String: %s\n",string); // print: String: a multiline string
remove_char_from_string(' ',string);
printf("String: %s\n",string); // print: String: amultilinestring
return 0;
}
';
// ========================
printf("%d [%s]\n",strlen(str), str);
}
This sets up two pointers initially the same. It then copies a character and always advances the source pointer. However, it only advances the destination pointer if the character wasn't a carriage return. That way, all carriage returns are overwritten by either the next character or the null terminator. The output is:
这设置了两个最初相同的指针。然后它复制一个字符并始终推进源指针。但是，如果字符不是回车符，它只会推进目标指针。这样，所有回车都会被下一个字符或空终止符覆盖。输出是：
##代码##This would be adequate for most strings. If your strings are truly massivein size (or this is something you need to do manytimes each second), you could look at a strchr-based solution since the library function will most likely be optimised.
这对于大多数字符串来说已经足够了。如果你的字符串是真正大规模的大小（或这是你需要做的事情很多次每秒），你可以看看在strchr基础的解决方案，因为库函数将最有可能得到优化。
回答by Pierre-Luc Simard
A carriage return or any other char is easy to replace in a string and even easier to replace. Your question does not really shows what you're looking for so I've included sample code for both removing and replacing a char in a string.
回车或任何其他字符很容易在字符串中替换，甚至更容易替换。您的问题并未真正显示您要查找的内容，因此我包含了用于删除和替换字符串中的字符的示例代码。
##代码##