Thread: How to read a text file into an array of strings?

In a program, I have a text file (called MyDictionary.txt) which has thousands of words in alphabetical order. I need to make a C program that reads in this text file and then makes an array called

char Words[# of total words in the text file][length of longest word].

How do i do that??

if it helps, this is kind of what the dictionary looks like, except many more words:

Aarhus
Aaron
Ababa
aback
abaft
abandon
if you could give me exactly how to do this that would be great, because I have very little time. Thanks for all the help.

Originally Posted by TheBigH

Do you know beforehand how many words there are, and how long the longest word is? If so,

Code:

char Words[NUMBER_OF_WORDS][LENGTH_OF_LONGEST_WORD+1]; /*the +1 leaves room for the \0 that terminates a string*/

To read from a file, use the fgets function.

Thanks for the reply, but no we do not get the number of words beforehand, we have to find that out ourselves, which is what I don't understand how to do.

The number of words does not need to be known. The length of the longest word does, though. Create a list of pointers to characters:

Code:

char * word_list[ MAXWORDLENGTH ];

Then read in each word from the file, allocate enough space using malloc for the word in the current spot in the list, copy the word into the space, and repeat until no more words.

Originally Posted by jwroblewski44

The number of words does not need to be known. The length of the longest word does, though. Create a list of pointers to characters:

Code:

char * word_list[ MAXWORDLENGTH ];

Then read in each word from the file, allocate enough space using malloc for the word in the current spot in the list, copy the word into the space, and repeat until no more words.

Well, actually it's the other way round. In your example "word_list" is an array of MAXWORDLENGTH pointers to char, i.e. you can store MAXWORDLENGTH words with any number of characters if you allocate enough memory for each word.

To the OP: Do you know how to dynamically allocate memory using malloc()?

If not you could read the file once, counting the lines (assuming there is only one word per line) to find out how many words are in the file. Then create the array and read the file a second time, now storing each word in the array. Not very efficient so I think you are supposed to use dynamic memory allocation, aren't you?

Bye, Andreas

Originally Posted by AndiPersti

Well, actually it's the other way round. In your example "word_list" is an array of MAXWORDLENGTH pointers to char, i.e. you can store MAXWORDLENGTH words with any number of characters if you allocate enough memory for each word.

To the OP: Do you know how to dynamically allocate memory using malloc()?

If not you could read the file once, counting the lines (assuming there is only one word per line) to find out how many words are in the file. Then create the array and read the file a second time, now storing each word in the array. Not very efficient so I think you are supposed to use dynamic memory allocation, aren't you?

Bye, Andreas

Ahh yes, thank you for pointing that out. I had the number of characters confused with the number of words.