How to use fgets() and store every line of a file using an array of char pointers?
The function fgets
doesn't allocate new memory. So in case of success eof == line
- that's right, it returns what you passed. You are overwriting it every time.
Try:
while((eof = fgets(line, 101, cf)) != NULL){
lines[i] = strdup(eof);
i++;
}
Of course you must remember to free(lines[i])
.
limitcracker
I am interested in Networking, Operating Systems and Information Systems. I like to say that I "know" C, Java, Python and PHP.
Updated on June 04, 2022Comments
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limitcracker almost 2 years
I wrote the program below in order to read every line of the file and then store each line in a array of char pointers for later use (like sorting only the pointers not the real strings). But the problem is that it keeps storing the same line.
Lets say that the file is called file.txt and has two(2) lines with text.
first sentence second sentence
The code I wrote is the following:
#include <stdio.h> #include <stdlib.h> #include <string.h> #include <strings.h> #include <unistd.h> int main(){ FILE *cf; cf = fopen("file.txt", "r"); char line[101]; char *lines[2]; char *eof; int i=0; while((eof = fgets(line, 101, cf)) != NULL){ lines[i] = eof; i++; } printf("%s\n", lines[0]); printf("%s\n", lines[1]); system("pause"); return 0; }
The output I get is:
second sentence second sentence
But I want to get:
first sentence second sentence
What I am doing wrong here?
-Thanks for your help :-)