Definition and Usage
定义和用法
The fscanf() function parses the input from an open file according to the specified format.
fscanf()函数的作用是:从文件中按照指定的格式输入。
Syntax
语法
fscanf(file,format,mixed) |
Parameter参数 | Description描述 |
file | Required. Specifies the file to check 必要参数。指定文件对象 |
format | Required. Specifies the format. 必要参数。指定格式 Possible format values: 可用的格式值: - %% - Returns a percent sign
%% - 返回一个“%” - %b - Binary number
%b – 二进制数 - %c - The character according to the ASCII value
%c – 某字符所对应的ASCII值 - %d - Signed decimal number
%d – 包含正负号的十进制数(可包含正负数) - %e - Scientific notation (e.g. 1.2e+2)
%e – 科学技术符号(例如:1.2e+2) - %u - Unsigned decimal number
%u – 不包含正负号的十进制数 - %f - Floating-point number (local settings aware)
%f – 浮点数字(本地属性) - %F - Floating-point number (not local settings aware)
%F – 浮点数字(非本地属性) - %o - Octal number
%o – 十进制数字 - %s - String
%s – 字符串 - %x - Hexadecimal number (lowercase letters)
%x – 十六进制数(小写字母) - %X - Hexadecimal number (uppercase letters)
%X – 十六进制数(大写字母) Additional format values. These are placed between the % and the letter (example %.2f): 其它的文本格式值。它是位于%和字母之间的(如:%.2f): - + (Forces both + and - in front of numbers. By default, only negative numbers are marked)
+(在数字前面加上‘+’或‘-’来定义数字的正负性;默认情况下,正数不做标记) - ' (Specifies what to use as padding. Default is space. Must be used together with the width specifier. Example: %'x20s (this uses "x" as padding)
’(指定使用旁白[padding]的类型。默认是空格space,它必须同时指定宽度,例如:%'x20s (这里使用 "x" 作为旁白[padding]) ) - - (Left-justifies the variable value)
-(向左调整变量值) - [0-9] (Specifies the minimum width held of to the variable value)
[0-9](指定了变量值的最小宽度) - .[0-9] (Specifies the number of decimal digits or maximum string length)
.[0-9](指定了十位数字或最大字符串长度) Note: If multiple additional format values are used, they must be in the same order as above. 注意:如果要使用多个上述的值,顺序必须按照上面的顺序,不能打乱。 |
mixed | Optional. 可选参数 |
Tips and Notes
注意点
Note: Any whitespace in the format string matches any whitespace in the input stream. This means that a tab (t) in the format string can match a single space character in the input stream.
注意:任何format的值中的空白部分[whitespace]与input内容相似;这意味着tab键(t)[制表符]和input内容的一个单一的空格[space]相似。