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PODynamic Array malloc empties separate array
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copied!<p>I am having an issue with dynamic arrays and <code>malloc</code>. I am fairly new to C so please excuse (and advise on) any rookie mistakes.</p> <p>The problem is I create an array (input_string in this case) and pass it to <code>func2</code>. Then in <code>func2</code> I do a test, print out the first element of input_string.</p> <p>This works as expected in the first printout before the <code>malloc</code>, but after the <code>malloc</code> it doesn't print anything. This seems weird to me since in between the to <code>printf</code> statements I do nothing to the input_string.</p> <p>I'm assuming that I am dealing with these arrays incorrectly, but I'm unsure.</p> <p>Here is a snippet of the code in question:</p> <p><strong>Updated</strong></p> <pre><code>... // includes not in snippet /* CONSTANTS */ #define LINE_LEN 80 /* Function declarations */ char* func1(void); char* func2(int tl, char* input_string); int main(void) { char* input_string; int tab_length; char* output_string; input_string = func1(); output_string = func2(tl, input_string); return 0; } char* func1(void) { char cur_char; char* input_ptr; char input_string[LINE_LEN]; while ((cur_char = getchar()) != '\n' && chars_read < 80) { // iterate and create the array here } input_ptr = &input_string[0]; /* set pointer to address of 0th index */ return input_ptr; } char* func2(int tl, char* input_string) { int n = 0, output_idx = 0; char* output_ptr; printf("\nBefore malloc: %c ", *(input_string)); output_ptr = malloc(tab_length * chars_read+1); if (output_ptr == NULL) { printf("Failed to allocate memory for output_ptr.\nExiting"); exit(1); } printf("\nAfter malloc: %c ", *(input_string)); ... return output_ptr; } </code></pre> <p>P.s.: Any undeclared variables have been declared outside of this snippet of code.</p> <p><strong>Update</strong></p> <p>Thanks for all the replies and advice. It is very much appreciated.</p>

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