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Light Poster
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| 18Dec2007,13:07 | #1 |
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Hi, I had a problem in reading a particular string of a text file in C++.
For example, I had a text file that looks like the one below: Code:
Variable = .iso.org.dod.internet.private.enterprises.9.9.273.1.3.1.1.3.1.8.105.118.116.108.95.97.112.49.0.2.45.4.155.81 Value = Integer32 -44 End of MIB subtree. Value = Integer32 " strings. My partially written code to read the file is given as below: Code:
apfile=fopen("ap1.txt","r+");
if (apfile==NULL)
{
cout<<"Error opening file ap1.txt"<<endl;
fclose (apfile);
return -1;
}
else
{
while (!feof(apfile))
{
}
}
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Ambitious contributor
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| 18Dec2007,19:32 | #2 |
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So do you want C or C++ ?
Because you've used a random mix of C and C++ API's in your snippet of code, so I'm wondering what exactly you're trying to learn. > but I donno how to read it without reading the "Variable = .iso... You have to read it, but there's nothing to stop you from throwing it away and reading another line, the line with the info you want. |
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Light Poster
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| 19Dec2007,11:58 | #3 |
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Well, sorry for the confusion cos my programming aren't tht good and I've just started picking up C/C++ programming.
My main purpose is to read the file, and to extract the integer "-44" value frm the text file, so I don really care if I'm using C or C++. But I'm still not sure of how to get rid of the first line and skipped to the second line, as the first line is pretty long and the length is random. anyway, thanks for ur time taken to reply to my question, greatly appreciate it! 
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Ambitious contributor
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| 19Dec2007,19:45 | #4 |
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I would suggest C++ then.
Use a std::string variable to store each line, and use the getline() method to read a whole line (it's length won't matter). |
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Light Poster
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| 20Dec2007,22:49 | #5 |
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Can I try to open the text and put it in a 2 dimensional array, then call the second line of the text file in array format and frm there to use str.at() method to get the value "-44"? Can I do tht? Is it possible?
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Ambitious contributor
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| 20Dec2007,23:17 | #6 |
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Sure you could do that.
http://www.cplusplus.com/reference/string/string/ But perhaps the find method (in a loop) to step over a number of spaces in the line would perhaps be more reliable. Why would you need a 2D array when you're only interested in the 2nd line? Just read the first line and throw it away, there's no need to store it. Try some ideas and see what happens
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