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POC - Array of strings (2D array) and memory allocation gets me unwanted characters
 

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  1. POC - Array of strings (2D array) and memory allocation gets me unwanted characters
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    <p>I have a tiny problem with my assignment. The whole program is about tree data structures but I do not have problems with that.</p> <p>My problem is about some basic stuff: reading strings from user input and then storing them in an array <em>list</em>.</p> <pre><code>char str[1000]; fgets(str, 1000, stdin); int x = 0; int y = 0; int z = 0; char **list; list = (char**)malloc((x+1)*sizeof(char)); list[x] = (char*)malloc((y+1)*sizeof(char)); while(str[z] != '\n') { list[x][y] = str[z]; z++; if(str[z] == ',') { x++; y = 0; list = (char**)realloc(list, (x+1) * sizeof(char*)); list[x] = (char*)malloc((y + 1)*sizeof(char)); z++; if(str[z] == ' ') // Skips space after the comma { z++; } } else if(str[z] == '\n') { break; } else { y++; list[x] = (char*)realloc(list[x], (y+1)*sizeof(char)); } } </code></pre> <p>I pass this list array into another function. As an example, inputs could be something like </p> <pre><code>Abcde, Fghijk, Lmnop, Qrstu </code></pre> <p>and I am trying to split each of these words into the array <em>list</em>.</p> <pre><code>Abcde Fghijk Lmnop Qrstu </code></pre> <p>When I try to output the strings I sometimes get weird, excessive characters such as upside down question marks and numbers.</p> <pre><code>printf("%s ", list[some_number]); </code></pre> <p>gets me</p> <pre><code>Fghijk¿ </code></pre> <p>or</p> <pre><code>Fghijk\200 </code></pre> <p>All of my program works as expected except for this minor problem which I am having trouble solving. Even with the same exact inputs the bugs may or may not appear. I am guessing it has to do with memory allocation?</p> <p>Thanks for your help!</p>
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    1. COWhen you use malloc there are no guarantees as to what is contained in the memory you have set aside, you should initialize it to NULL, or at the very least null terminate your strings.
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    2. COCan I see the other function that you're passing the stuff to? Also, how are these args being passed into the program? File, console, etc.?
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      1. USnerdenator
 

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