Random line from txt file

**dogbert234** · 05-31-2005

Hi,
I hope this question isn't to stupid, but how can I get a random line from txt file? Google didn't help me much at that point, so maybe you could

Best regards,
dogbert234-

**Salem** · 05-31-2005

Read them all into an array of lines
Count how many you read (=n)
Pick one of them (array[rand()%n)

**dogbert234** · 05-31-2005

I appology for my stupidity, but how can I read that to array?

**Salem** · 05-31-2005

Well a std::vector of std::string would seem to be the way to go.

**xErath** · 05-31-2005

or maybe fgets would do the trick

**major_small** · 06-01-2005

another (possibly less efficient) method:

you could pick a random number and ignore that many lines... for example:

Code:

for(i=0;i<randomNumber;i++)  //loop through until you reach a certain line
{
    infile.ignore(32000,'\n');  //ignore a line
}

of course (or maybe not) this takes two reads of the file (which would slow it immensely) or prior knowledge of how many lines there are in it.

Thread: Random line from txt file