The usage of sscanf in C language

The following is a detailed analysis of the use of the SSCANF function in C language, the need for friends under the reference

Name:
sscanf ()-Reads data from a string that matches the specified format.

Copy Code code as follows:


function Prototype:
Int sscanf (String str, String fmt, mixed var1, mixed var2 ...);
int scanf (const char *format [, argument] ...);

Description:
sscanf is similar to scanf and is used for input, except that the latter takes the screen (stdin) as the input source, with a fixed string as the input source.
The format can be one or more {%[*] [width] [{h | l | I64 | L}]type | ' ' | '/T ' | '/n ' | Non-% symbol}
Note:
1, * can also be used in the format, (that is,%*d and%*s) with an asterisk (*) indicates that skipping this data is not read. (that is, do not read this data into the parameter)
2. {A|b|c} indicates that A,b,c is selected, [d], that it can have D or not d.
3. Width represents the reading breadth.
4, {h | l | I64 | L}: The size of the parameter, usually H represents a single-byte Size,i 2 byte size,l represents 4 byte size (double exception), and L64 represents 8 byte size.
5, type: This is a lot of, is%s,%d and so on.
6, Special:%*[width] [{h | l | I64 | L}]type indicates that the condition is filtered out and the value is not written to the target parameter

Support for collection operations:
%[a-z] means to match any character in a to Z, greedy (as many matches as possible)
%[ab '] Match A, B, ' a member, greedy sex
%[^a] matches any character that is not a, greedy
Here is an example program

Copy Code code as follows:

/*****************************************************


* * NAME:SSCANF.C


* * Author:gzshun


* * version:1.0


* * date:2011-12


* * description:sscanf function


******************************************************/


#include <stdio.h>


#include <stdlib.h>


#include <string.h>


static void Sscanf_test (void);


static void Sscanf_test (void)


{


int ret;


Char *string;


int digit;


Char buf1[255];


Char buf2[255];


Char buf3[255];


Char buf4[255];


/*1. The simplest usage/


string = "Beijing 123";


ret = sscanf (string,%s%s%d, buf1, BUF2, &digit);


printf ("1.string=%sn", string);


printf ("1.ret=%d, buf1=%s, buf2=%s, Digit=%dnn", ret, BUF1, buf2, digit);


 /*


* Execution Results:


**1.ret=3, Buf1=china, buf2=beijing, digit=123


* Can see that the return value of SSCANF is the number of parameters read


 */


/*2. Take the specified length of the string/


string = "123456789";


sscanf (String, "%5s", BUF1);


printf ("2.string=%sn", string);


printf ("2.buf1=%snn", BUF1);


 /*


* Execution Results:


**2.buf1=12345


 */


/*3. String to the specified character * *


string = "123/456";


sscanf (String, "%[^/]", BUF1);


printf ("3.string=%sn", string);


printf ("3.buf1=%snn", BUF1);


 /*


* Execution Results:


**3.buf1=123


 */


/*4. String to the specified character set * *


string = "123abcABC";


sscanf (String, "%[^a-z]", BUF1);


printf ("4.string=%sn", string);


printf ("4.buf1=%snn", BUF1);


 /*


* Execution Results:


**4.BUF1=123ABC


 */


/*5. Takes a string containing only the specified character set */


string = "0123abcABC";


sscanf (String, "%[0-9]%[a-z]%[a-z]", Buf1, Buf2, BUF3);


printf ("5.string=%sn", string);


printf ("5.buf1=%s, buf2=%s, Buf3=%snn", Buf1, Buf2, BUF3);


 /*


* Execution Results:


**5.buf1=123, BUF2=ABC, Buf3=abc


 */


/*6. Gets the string in the middle of the specified character. */


string = "ios<android>wp7";


SSCANF (String, "%*[^<]<%[^>]", BUF1);


printf ("6.string=%sn", string);


printf ("6.buf1=%snn", BUF1);


 /*


* Execution Results:


**6.buf1=android


 */


/*7. Specifies the string to skip * * *


string = "iosvsandroid";


sscanf (String, "%[a-z]vs%[a-z]", BUF1, BUF2);


printf ("7.string=%sn", string);


printf ("7.buf1=%s, Buf2=%snn", Buf1, BUF2);


 /*


* Execution Results:


**7.buf1=ios, Buf2=android


 */


/*8. Split a string separated by a character. */


string = "android-iphone-wp7";


 /*


* * string via '-', followed by delimiter '-',


* * played a role in filtration, somewhat similar to the 7th


 */


sscanf (String, "%[^-]-%[^-]-%[^-]", Buf1, Buf2, BUF3);


printf ("8.string=%sn", string);


printf ("8.buf1=%s, buf2=%s, Buf3=%snn", Buf1, Buf2, BUF3);


 /*


* Execution Results:


**8.buf1=android, Buf2=iphone, buf3=wp7


 */


/*9. Extract Email address/


string = "email:beijing@sina.com.cn";


sscanf (String, "%[^:]:%[^@]@%[^."). %s ", Buf1, Buf2, BUF3, BUF4);


printf ("9.string=%sn", string);


printf ("9.buf1=%s, buf2=%s, buf3=%s, Buf4=%snn", Buf1, Buf2, BUF3, BUF4);


 /*


* Execution Results:


**9.buf1=email, buf2=beijing, Buf3=sina, buf4=com.cn


 */


/*10. Filter out strings that you don't want to intercept or need--supplement,


* * Adds a * number after the%, which represents filtering this string and does not read


 */


string = "android iphone wp7";


sscanf (String, "%s%*s%s", BUF1, BUF2);


printf ("10.string=%sn", string);


printf ("10.buf1=%s, Buf2=%snn", Buf1, BUF2);


 /*


* Execution Results:


**10.android wp7


 */


}


int main (int argc, char **argv)


{


sscanf_test ();





return 0;


}


/*


* * Test program


* * Environment:


**linux ubuntu 2.6.32-24-generic-pae #39-ubuntu SMP Wed June 07:39:26 UTC i686 gnu/linux


**GCC version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)


**


gzshun@ubuntu:~/c/sscanf$ gcc sscanf.c-o sscanf


gzshun@ubuntu:~/c/sscanf$./sscanf


1.string=china Beijing 123


1.ret=3, Buf1=china, buf2=beijing, digit=123


2.string=123456789


2.buf1=12345


3.string=123/456


3.buf1=123


4.STRING=123ABCABC


4.BUF1=123ABC


5.STRING=0123ABCABC


5.buf1=0123, BUF2=ABC, Buf3=abc


6.string=ios<android>wp7


6.buf1=android


7.string=iosvsandroid


7.buf1=ios, Buf2=android


8.string=android-iphone-wp7


8.buf1=android, Buf2=iphone, buf3=wp7


9.string=email:beijing@sina.com.cn


9.buf1=email, buf2=beijing, Buf3=sina, buf4=com.cn


10.string=android iphone wp7


10.buf1=android, buf2=wp7


*/