[英]C - Read string with integers from formatted text file
I have a text file following this format: 我有一个采用以下格式的文本文件:
Thing 1: 0 0 128
Other thing: 255 64 255
Something else: 32 32 8
I intend to add more to this file eventually but the format will remain the same. 我打算最终向此文件中添加更多内容,但格式将保持不变。 What I want to do is read everything before the colon into a string and everything after it as an integer.
我想要做的是将冒号之前的所有内容读取为字符串,并将其后面的所有内容读取为整数。 I've tried this:
我已经试过了:
fscanf((file = fopen("colors.txt", "r")) == NULL){
return -1;
}
fscanf("%s: %d %d %d", colorStr, &r, &g, &b);
while(!feof(file)){
printf("%s: %d %d %d", colorStr, r, g, b);
fscanf(file, "%s: %d %d %d", colorStr, &r, &g, &b);
}
fclose(file);
However, I get this output: 但是,我得到以下输出:
Thing 1:: 0 0 0
0: 0 0 0
0: 0 0 0
128: 0 0 0
And so on. 等等。 Ideally, the output should read like this:
理想情况下,输出应如下所示:
Thing 1: 0 0 128
Other thing: 255 64 255
Something else: 32 32 8
How can I fix this? 我怎样才能解决这个问题? The
colorStr
, r
, g
, and b
variables were set up earlier in the program. colorStr
, r
, g
和b
变量是在程序的前面设置的。
The problem with your code is that the text contains spaces, which %s
does not allow. 您的代码的问题是文本包含空格,
%s
不允许使用空格。
Changing the format string to %[^:]
will fix this problem. 将格式字符串更改为
%[^:]
将解决此问题。
However, the code would remain vulnerable to buffer overrun. 但是,代码仍然容易受到缓冲区溢出的影响。 Make sure that your format string includes the max size of
colorStr
to prevent it: 确保您的格式字符串包括
colorStr
的最大大小,以防止出现这种情况:
char colorStr[100];
fscanf(file, " %99[^:]: %d %d %d", colorStr, &r, &g, &b);
Your code uses feof(file)
, which is incorrect. 您的代码使用
feof(file)
,这是不正确的。 You should put fscanf
into loop header. 您应该将
fscanf
放入循环标头中。 This would let you remove the duplicate fscanf
call before the loop: 这将使您在循环之前删除重复的
fscanf
调用:
while(fscanf(file, " %99[^:]: %d %d %d", colorStr, &r, &g, &b) == 4) {
printf("%s: %d %d %d\n", colorStr, r, g, b);
}
Note the space in front of the leading %
format specifier. 请注意前导
%
格式说明符前面的空格。 It instructs fscanf
to skip the trailing spaces and/or '\\n'
from the previous line. 它指示
fscanf
跳过前一行的尾随空格和/或'\\n'
。
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