[求助]一个关于scanf函数的问题
我在网上找了很多关于scanf函数的用法说明，但是没有找到针对我这个问题出现的解决方法。可能是我对scanf函数还不熟悉导致的。
先说明一下问题：
我要解析一段字符串，其格式为：#运营商名字#APN#IP#port#用户名#密码#主页#。
现在问题是当用户名和密码为空的时候，会连续有3个#，然后按照我的解析格式，scanf函数就扫不出来了。
以下为我在VC9中的调试代码。
调试断点截图：
![[]一个关于scanf函数的有关问题](http://img.reader8.net/uploadfile/jiaocheng/20140134/2730/2014012700302242644.jpg)
scanf
[解决办法]
哪来的scanf啊 明明是sscanf
你跟到sscanf函数中，看这个函数怎么处理的，自己重新写一个解析的函数也不难吧
[解决办法]
1. 找sscanf的源代码，就知道为什么没有解析了
2. 用正则表达式
[解决办法]
看看帮助文档可能更快，毕竟源码理解耗时，理解也可能出现偏差。
sscanf, swscanfSee Also
fscanf
[解决办法]
scanf
[解决办法]
sprintf
[解决办法]
_snprintf
Requirements
OS Versions: Windows CE 2.0 and later.
Header: stdio.h, stdlib.h.
Link Library: coredll.dll.
Read formatted data from a string.
int sscanf( const char *buffer, const char *format [, argument ] ... );
int swscanf( const wchar_t *buffer, const wchar_t *format [, argument ] ... );
Parameters
buffer
Stored data.
format
Format-control string.
argument
Optional arguments.
Libraries
All versions of the C run-time libraries.
Return Values
Each of these functions returns the number of fields successfully converted and assigned; the return value does not include fields that were read but not assigned. A return value of 0 indicates that no fields were assigned. The return value is EOF for an error or if the end of the string is reached before the first conversion.
Remarks
The sscanf function reads data from buffer into the location given by each argument. Every argument must be a pointer to a variable with a type that corresponds to a type specifier in format.
The format argument controls the interpretation of the input fields and has the same form and function as the format argument for the scanf function; see scanf for a complete description of format. If copying takes place between strings that overlap, the behavior is undefined.
swscanf is a wide-character version of sscanf; the arguments to swscanf are wide-character strings. sscanf does not handle multibyte hexadecimal characters. swscanf does not handle Unicode fullwidth hexadecimal or "compatibility zone" characters. Otherwise, swscanf and sscanf behave identically.
Generic-Text Routine Mappings
TCHAR.H Routine _UNICODE Defined
_stscanf swscanf
For more information about TCHAR.H routines, see Generic Text Mappings.
Example
/* SSCANF.C: This program uses sscanf to read data items
from a string named tokenstring, then displays them.
*/
#include <stdio.h>
void main( void )
{
char tokenstring[] = "15 12 14...";
char s[81];
char c;
int i;
float fp;
/* Input various data from tokenstring: */
sscanf( tokenstring, "%s", s );
sscanf( tokenstring, "%c", &c );
sscanf( tokenstring, "%d", &i );
sscanf( tokenstring, "%f", &fp );
/* Output the data read */
printf( "String = %s\n", s );
printf( "Character = %c\n", c );
printf( "Integer: = %d\n", i );
printf( "Real: = %f\n", fp );
}
Output
String = 15
Character = 1
Integer: = 15
Real: = 15.000000
Requirements
OS Versions: Windows CE 2.0 and later.
Header: stdio.h, stdlib.h.
Link Library: coredll.dll.
scanf, wscanfSee Also
fscanf
[解决办法]
printf
[解决办法]
sprintf
[解决办法]
sscanf
Requirements
OS Versions: Windows CE 2.0 and later.
Header: stdlib.h.
Link Library: coredll.dll.
Read formatted data from the standard input stream.
int scanf(
const char* format [,argument]...
);
int wscanf(
const wchar_t* format [,argument]...
);
Parameters
format
Format control string.
argument
Optional arguments.
Return Values
Both scanf and wscanf return the number of fields converted and assigned; the return value does not include fields that were read but not assigned.
A return value of 0 indicates that no fields were assigned.
The return value is EOF for an error or if the end-of-file character or the end-of-string character is encountered in the first attempt to read a character.
Remarks
The scanf function reads data from the standard input stream stdin and writes the data into the location given by argument.
Each argument must be a pointer to a variable of a type that corresponds to a type specifier in format.
If copying takes place between strings that overlap, the behavior is undefined.
wscanf is a wide-character version of scanf; the format argument to wscanf is a wide-character string. wscanf and scanf behave identically otherwise.
Generic-Text Routine Mappings
TCHAR.H Routine _UNICODE Defined
_tscanf wscanf
For more information about TCHAR.H routines, see Generic Text Mappings.
For more information, see Format Specification Fields — scanf functions and wscanf Functions.
Example
/* SCANF.C: This program uses the scanf and wscanf functions
* to read formatted input.
*/
#include <stdio.h>
void main( void )
{
int i, result;
float fp;
char c, s[81];
wchar_t wc, ws[81];
printf( "\n\nEnter an int, a float, two chars and two strings\n");
result = scanf( "%d %f %c %C %s %S", &i, &fp, &c, &wc, s, ws );
printf( "\nThe number of fields input is %d\n", result );
printf( "The contents are: %d %f %c %C %s %S\n", i, fp, c, wc, s, ws);
wprintf( L"\n\nEnter an int, a float, two chars and two strings\n");
result = wscanf( L"%d %f %hc %lc %S %ls", &i, &fp, &c, &wc, s, ws );
wprintf( L"\nThe number of fields input is %d\n", result );
wprintf( L"The contents are: %d %f %C %c %hs %s\n", i, fp, c, wc, s, ws);
}
Output
Enter an int, a float, two chars and two strings
71
98.6
h
z
Byte characters
The number of fields input is 6
The contents are: 71 98.599998 h z Byte characters
Enter an int, a float, two chars and two strings
36
92.3
y
n
Wide characters
The number of fields input is 6
The contents are: 456 92.300003 y n Wide characters
Requirements
OS Versions: Windows CE 2.0 and later.
Header: stdlib.h.
Link Library: coredll.dll.
格式化参数规格：
Format Specification Fields: scanf and wscanf FunctionsSee Also
scanf Width Specification
A format specification has the following form:
%[*] [width] [{h
[解决办法]
l
[解决办法]
I64
[解决办法]
L}]type
The format argument specifies the interpretation of the input and can contain one or more of the following:
White-space characters: blank (' '); tab ('\t'); or newline ('\n').
A white-space character causes scanf to read, but not store, all consecutive white-space characters in the input up to the next nonwhite-space character.
One white-space character in the format matches any number (including 0) and combination of white-space characters in the input.
Nonwhite-space characters, except for the percent sign (%).
A nonwhite-space character causes scanf to read, but not store, a matching nonwhite-space character.
If the next character in stdin does not match, scanf terminates.
Format specifications, introduced by the percent sign (%).
A format specification causes scanf to read and convert characters in the input into values of a specified type. The value is assigned to an argument in the argument list.
The format is read from left to right.
Characters outside format specifications are expected to match the sequence of characters in stdin; the matching characters in stdin are scanned but not stored. If a character in stdin conflicts with the format specification, scanf terminates, and the character is left in stdin as if it had not been read.
When the first format specification is encountered, the value of the first input field is converted according to this specification and stored in the location that is specified by the first argument.
The second format specification causes the second input field to be converted and stored in the second argument, and so on through the end of the format string.
An input field is defined as all characters up to the first white-space character (space, tab, or newline), or up to the first character that cannot be converted according to the format specification, or until the field width (if specified) is reached.
If there are too many arguments for the given specifications, the extra arguments are evaluated but ignored.
The results are unpredictable if there are not enough arguments for the format specification.
Each field of the format specification is a single character or a number signifying a particular format option.
The type character, which appears after the last optional format field, determines whether the input field is interpreted as a character, a string, or a number.
The simplest format specification contains only the percent sign (%) and a type character (for example, %s).
If a percent sign is followed by a character that has no meaning as a format-control character, that character and the following characters (up to the next percent sign) are treated as an ordinary sequence of characters, that is, a sequence of characters that must match the input.
For example, to specify that a percent-sign character is to be input, use %%.
An asterisk (*) following the percent sign suppresses assignment of the next input field, which is interpreted as a field of the specified type. The field is scanned but not stored.
以上信息来自MSDN，供参考。
[解决办法]
#include <stdio.h>
#include <string.h>
char string[80];
char seps1[3];
char seps2[3];
char *token;
char *zzstrtok (
char *string,
const char *control1,//连续出现时视为中间夹空token
const char *control2 //连续出现时视为中间无空token
)
{
unsigned char *str;
const unsigned char *ctrl1 = control1;
const unsigned char *ctrl2 = control2;
unsigned char map1[32],map2[32];
static char *nextoken;
static char flag=0;
unsigned char c;
int L;
memset(map1,0,32);
memset(map2,0,32);
do {
map1[*ctrl1 >> 3]
[解决办法]
= (1 << (*ctrl1 & 7));
} while (*ctrl1++);
do {
map2[*ctrl2 >> 3]
[解决办法]
= (1 << (*ctrl2 & 7));
} while (*ctrl2++);
if (string) {
if (control2[0]) {
L=strlen(string);
while (1) {
c=string[L-1];
if (map2[c >> 3] & (1 << (c & 7))) {
L--;
string[L]=0;
} else break;
}
}
if (control1[0]) {
L=strlen(string);
c=string[L-1];
if (map1[c >> 3] & (1 << (c & 7))) {
string[L]=control1[0];
string[L+1]=0;
}
}
str=string;
}
else str=nextoken;
string=str;
while (1) {
if (0==flag) {
if (!*str) break;
if (map1[*str >> 3] & (1 << (*str & 7))) {
*str=0;
str++;
break;
} else if (map2[*str >> 3] & (1 << (*str & 7))) {
string++;
str++;
} else {
flag=1;
str++;
}
} else if (1==flag) {
if (!*str) break;
if (map1[*str >> 3] & (1 << (*str & 7))) {
*str=0;
str++;
flag=0;
break;
} else if (map2[*str >> 3] & (1 << (*str & 7))) {
*str=0;
str++;
flag=2;
break;
} else str++;
} else {//2==flag
if (!*str) return NULL;
if (map1[*str >> 3] & (1 << (*str & 7))) {
str++;
string=str;
flag=0;
} else if (map2[*str >> 3] & (1 << (*str & 7))) {
str++;
string=str;
} else {
string=str;
str++;
flag=1;
}
}
}
nextoken=str;
if (string==str) return NULL;
else return string;
}
void main()
{
strcpy(string,"A \tstring\t\tof ,,tokens\n\nand some more tokens, ");
strcpy(seps1,",\n");strcpy(seps2," \t");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"1234
[解决办法]
LIYI
[解决办法]
China
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK");
strcpy(seps1,"
------解决方案--------------------
");strcpy(seps2," ");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"1234
[解决办法]
LIYI
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK");
strcpy(seps1,"");strcpy(seps2,"
[解决办法]
");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"1234
[解决办法]
LIYI
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK");
strcpy(seps1,"
[解决办法]
");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"a");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"a,b");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"a,,b");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",a");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,"a,");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",a,,b");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",,a,,b,,");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",,");
strcpy(seps1,",");strcpy(seps2,"");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
strcpy(string,",,,");
strcpy(seps1,",");strcpy(seps2," ");
printf("\n[%s]\nTokens:\n",string);
token=zzstrtok(string,seps1,seps2);
while (token!=NULL) {
printf(" <%s>",token);
token=zzstrtok(NULL,seps1,seps2);
}
}
//
//[A string of ,,tokens
//
//and some more tokens,]
//Tokens:
// <A>, <string>, <of>, <>, <tokens>, <>, <and>, <some>, <more>, <tokens>, <>,
//[1234
[解决办法]
LIYI
[解决办法]
China
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK]
//Tokens:
// <1234>, <LIYI>, <China>, <010>, <201110260000>, <OK>,
//[1234
[解决办法]
LIYI
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK]
//Tokens:
// <1234>, <LIYI>, <010>, <201110260000>, <OK>,
//[1234
[解决办法]
LIYI
[解决办法]
010
[解决办法]
201110260000
[解决办法]
OK]
//Tokens:
// <1234>, <LIYI>, <>, <010>, <201110260000>, <OK>,
//[a]
//Tokens:
// <a>,
//[a,b]
//Tokens:
// <a>, <b>,
//[a,,b]
//Tokens:
// <a>, <>, <b>,
//[,a]
//Tokens:
// <>, <a>,
//[a,]
//Tokens:
// <a>, <>,
//[,a,,b]
//Tokens:
// <>, <a>, <>, <b>,
//[,,a,,b,,]
//Tokens:
// <>, <>, <a>, <>, <b>, <>, <>,
//[,]
//Tokens:
// <>, <>,
//[,,]
//Tokens:
// <>, <>, <>,
//[,,,]
//Tokens:
// <>, <>, <>, <>,
[解决办法]
武林至尊，宝刀屠龙，号令天下，莫敢不从：
![[]一个关于scanf函数的有关问题](http://img.reader8.net/uploadfile/jiaocheng/20140134/2730/2014012700302242645.gif)
倚天不出，谁与争锋：
![[]一个关于scanf函数的有关问题](http://img.reader8.net/uploadfile/jiaocheng/20140134/2730/2014012700302242646.gif)
C++ String Toolkit (StrTk) Tokenizer http://www.codeproject.com/Articles/23198/C-String-Toolkit-StrTk-Tokenizer
![[]一个关于scanf函数的有关问题](http://img.reader8.net/uploadfile/jiaocheng/20140134/2730/2014012700302242647.gif)