I want to split a string into tokens and save data into variables. I have the following string:
我想将字符串分割成记号并将数据保存到变量中。我有以下字符串:
John|Doe|Melbourne|6270|AU
约翰墨尔本| | Doe | 6270 |盟
I need to split it by |
and every token keep as variable so I can use them in my program, like:
我需要将它除以|,每个令牌都作为变量保存,这样我就可以在我的程序中使用它们,比如:
fname = "John"
lname = "Doe"
city = "Melbourne"
zip = "6270"
country = "AU"
tried this so far, I can access first token the rest I don't know how (besides a while loop that doesn't help me):
到目前为止,我可以访问第一个令牌,其余的我不知道如何(除了一个不帮助我的while循环):
#include <stdio.h>
#include <string.h>
int main (void) {
char str[] = "John|Doe|Melbourne|6270|AU";
strtok(str, "|");
printf("%s\n", str);
return 0;
}
5 个解决方案
#1
9
char fname[32], lname[32], city[32], zip[32], country[32];
strcpy(fname, strtok(str , "|"));
strcpy(lname, strtok(NULL, "|"));
strcpy(city , strtok(NULL, "|"));
strcpy(zip , strtok(NULL, "|"));
strcpy(country, strtok(NULL, "|"));
printf("%s\n", fname);
printf("%s\n", lname);
printf("%s\n", city);
printf("%s\n", zip);
printf("%s\n", country);
#2
5
If the format is constant, you can use sscanf()
:
如果格式是常量,可以使用sscanf():
char fname[32], lname[32], city[32], zip[16], country[8];
if(sscanf(str, "%31[^|]|%31[^|]|%31[^|]|%15[^|]%7s",
fname, lname, city, zip, country) == 5)
{
}
This uses the %[]
character set format specifier to grab "everything except a vertical bar". The width is included to prevent buffer overruns.
这使用%[]字符集格式说明符来获取“除了垂直条之外的所有内容”。宽度包含在其中,以防止缓冲区溢出。
#3
3
just keep on calling strtok
继续打电话给斯特托克
char* name = strtok(str, "|");
char* surname = strtok(NULL, "|");
...
#4
3
strtok
returns a pointer to the token; pass NULL as the first argument to retrieve successive tokens:
strtok返回指向令牌的指针;传递NULL作为检索连续令牌的第一个参数:
#define FIELD_LENGTH 20
#define NUM_FIELDS 5
...
char target[NUM_FIELDS][FIELD_LENGTH];
int field = 0;
...
while ( get_next_string( str )) // where get_next_string retrieves your next
{ // delimited string
char *token = strtok( str, "|" );
while ( token )
{
strcpy( target[i++], token );
token = strtok( NULL, "|" );
}
}
Edit
编辑
To address Golgauth's comment, there are some important things to remember about using strtok
:
要解决高华斯的评论,使用strtok有一些重要的事情要记住:
- It modifies the input string by replacing each occurrence of the delimiter with a 0, meaning it cannot be used on a string literal. If you want to preserve the original string, you will have to make a copy to pass to
strtok
; - 它修改输入字符串,将每次出现的分隔符替换为0,这意味着它不能用于字符串文字。如果要保留原始字符串,则必须复制到strtok;
- It uses a single, static buffer to store the string it's modifying, making it non-reentrant - if multiple threads make calls to
strtok
to tokenize different strings, they'll wind up stepping on each other (this is known as a race condition, where the behavior of the program depends on which thread gets access to something first). Also, you can't nest calls to strtok (that is, get a token, then split it into subtokens, then get the next token); - 它使用一个单一的静态缓冲区存储字符串修改,使其不可重入,如果多个线程调用strtok标记不同的字符串,最终他们会互相踩(这就是所谓的竞争条件,程序的行为取决于哪个线程可以获得第一)。另外,不能嵌套对strtok的调用(即获取一个令牌,然后将其分割为子令牌,然后获取下一个令牌);
The online 2011 standard mentions a safer (and IINM re-entrant) alternative, strtok_s
, as part of Annex K (Bounds-checking interfaces); some implementations also provide a strtok_r
function which is re-entrant.
2011在线标准提到了一种更安全(和IINM可重入)的替代方案strtok_s,作为附件K(绑定检查接口)的一部分;有些实现还提供了可重入的strtok_rfunction。
#5
2
You can use sscanf with that (it can scan strings up to a given delimiter)
可以使用sscanf(它可以将字符串扫描到给定的分隔符)
int n;
char fname[128]= "", lname[128]= "", city[128]= "", zipcode[128]= "", country[128]= "";
n= sscanf str("%127[^|]|%127[^|]|%127[^|]|%127[^|]|%127s", fname, lname, city, zipcode, country);
if (n==5) { // five fields scanned
}
#1
9
char fname[32], lname[32], city[32], zip[32], country[32];
strcpy(fname, strtok(str , "|"));
strcpy(lname, strtok(NULL, "|"));
strcpy(city , strtok(NULL, "|"));
strcpy(zip , strtok(NULL, "|"));
strcpy(country, strtok(NULL, "|"));
printf("%s\n", fname);
printf("%s\n", lname);
printf("%s\n", city);
printf("%s\n", zip);
printf("%s\n", country);
#2
5
If the format is constant, you can use sscanf()
:
如果格式是常量,可以使用sscanf():
char fname[32], lname[32], city[32], zip[16], country[8];
if(sscanf(str, "%31[^|]|%31[^|]|%31[^|]|%15[^|]%7s",
fname, lname, city, zip, country) == 5)
{
}
This uses the %[]
character set format specifier to grab "everything except a vertical bar". The width is included to prevent buffer overruns.
这使用%[]字符集格式说明符来获取“除了垂直条之外的所有内容”。宽度包含在其中,以防止缓冲区溢出。
#3
3
just keep on calling strtok
继续打电话给斯特托克
char* name = strtok(str, "|");
char* surname = strtok(NULL, "|");
...
#4
3
strtok
returns a pointer to the token; pass NULL as the first argument to retrieve successive tokens:
strtok返回指向令牌的指针;传递NULL作为检索连续令牌的第一个参数:
#define FIELD_LENGTH 20
#define NUM_FIELDS 5
...
char target[NUM_FIELDS][FIELD_LENGTH];
int field = 0;
...
while ( get_next_string( str )) // where get_next_string retrieves your next
{ // delimited string
char *token = strtok( str, "|" );
while ( token )
{
strcpy( target[i++], token );
token = strtok( NULL, "|" );
}
}
Edit
编辑
To address Golgauth's comment, there are some important things to remember about using strtok
:
要解决高华斯的评论,使用strtok有一些重要的事情要记住:
- It modifies the input string by replacing each occurrence of the delimiter with a 0, meaning it cannot be used on a string literal. If you want to preserve the original string, you will have to make a copy to pass to
strtok
; - 它修改输入字符串,将每次出现的分隔符替换为0,这意味着它不能用于字符串文字。如果要保留原始字符串,则必须复制到strtok;
- It uses a single, static buffer to store the string it's modifying, making it non-reentrant - if multiple threads make calls to
strtok
to tokenize different strings, they'll wind up stepping on each other (this is known as a race condition, where the behavior of the program depends on which thread gets access to something first). Also, you can't nest calls to strtok (that is, get a token, then split it into subtokens, then get the next token); - 它使用一个单一的静态缓冲区存储字符串修改,使其不可重入,如果多个线程调用strtok标记不同的字符串,最终他们会互相踩(这就是所谓的竞争条件,程序的行为取决于哪个线程可以获得第一)。另外,不能嵌套对strtok的调用(即获取一个令牌,然后将其分割为子令牌,然后获取下一个令牌);
The online 2011 standard mentions a safer (and IINM re-entrant) alternative, strtok_s
, as part of Annex K (Bounds-checking interfaces); some implementations also provide a strtok_r
function which is re-entrant.
2011在线标准提到了一种更安全(和IINM可重入)的替代方案strtok_s,作为附件K(绑定检查接口)的一部分;有些实现还提供了可重入的strtok_rfunction。
#5
2
You can use sscanf with that (it can scan strings up to a given delimiter)
可以使用sscanf(它可以将字符串扫描到给定的分隔符)
int n;
char fname[128]= "", lname[128]= "", city[128]= "", zipcode[128]= "", country[128]= "";
n= sscanf str("%127[^|]|%127[^|]|%127[^|]|%127[^|]|%127s", fname, lname, city, zipcode, country);
if (n==5) { // five fields scanned
}