I want to sort strings from file; this code compiles well, but it stops working in line 29, when I do words_array[i] = strdup(line);.
From debugger I have "program received signal sigsegv segmentation fault"
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int comparator ( const void * elem1, const void * elem2 )
{
return strcmp( *(const char**) elem1, *(const char**) elem2);
}
int main()
{
char filename[]="dane.txt";
FILE* fp;
char* line = NULL;
size_t len = 0;
char** words_array = NULL;
int i = 0,j; // number of elements
// read list from file
if( ( fp = fopen(filename, "r") ) == NULL ) {
fprintf(stderr, "Cannot open source file %s!\n", filename);
exit(1);
}
for(; fgets(line, len, fp) != NULL; ++i) {
// put word in array
words_array = realloc(words_array, sizeof(char*) * (i + 1) );
words_array[i] = strdup(line);
}
fclose(fp);
free(line);
// sort it
qsort(words_array, i, sizeof(char*), comparator);
if( ( fp = fopen(filename, "a+") ) == NULL ) {
fprintf(stderr, "Cannot open source file %s!\n", filename);
exit(1);
}
// write to file and free dynamically allocated memory
for(j = 0; j < i; ++j) {
fprintf(fp, "%s", words_array[j]);
free(words_array[j]);
}
free(words_array);
fclose(fp);
return 0;
}
