Thread: Read file into array

The "import" of the data would best be done by fgets() to read a line, and then suitable line-parsing. Depending on the format you have two choices:
1. manually separate out the portions of the string, using for example strtok(). Once you have the component of a string, you would use strcpy() to copy string data and the strtod(), strtol() functions to convert to double and long respectively/
2. use sscanf() to read the string.

Which one of the above you use would depend on the exact formatting of the string. If you could post a few "typical" lines of your data it would help.

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Mats

Depends on the format of the file and exactly how much you have to read. If it's line-based entries of numbers and strings, you could create a struct for each entry and a function to read such a line from a FILE *.

Originally Posted by ZaC

I think you could like the example in this reference to fread() function: http://www.cplusplus.com/reference/c...dio/fread.html

Although fread() tends to be tricky to use with text-input. It would possibly work out OK if every line is the same length. But the benefit over fgets() is small - for large files, the majority of the time consumed would be idle-time waiting for the disk to deliver the file-content. On a small file (and 200 lines is definitely small in this circumstance), I would expect fgets() to read the whole file in less than 0.1 seconds, and you wouldn't be able to see a noticeable improvement on that in using fread(), but with a distinct loss in flexibility.

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Mats

. . . but if you're using sscanf() or strtol(), you don't have to, because those functions (generally) ignore whitespace.

Still, here's how you can remove the newline if you so choose:

Code:

#include <string.h>

char buffer[BUFSIZ], *p;
fgets(buffer, sizeof(buffer), stdin);
if((p = strchr(buffer, '\n'))) *p = 0;

If you really meant char * to float, then you could use strtod() to convert it to a double.

If you can guarantee that there is no whitespace in the label, then that is easily done by reading the label string until you hit upon whitespace. Otherwise, this will be slightly more difficult.