c - Why this code does what it does? -

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there's recent question posted. here's link:
output sorted in weird way

i know how it's wrong, i'm trying figure out is, why produces it's output way is?
after changing getch() getchar() compiled , run few times. changes first 4 letters. can't see where change actuallly takes place in code.
appreciated.

this happens in swap function:

//swapping function void swap(char **first, char **second) ...

the op assumed 'char *' integral type, , moving around move the string around. second part swap function should accept pointers data, not actual data. swaps addresses of data , not touch data itself.

however, when called char * *, goes wrong. swaps data @ address of 'a pointer to'. input not "pointer to-pointer to".

'pointer to' has sizeof int on systems (where 'most' subjective assessment -- search "sizeof pointer" discussions , opinions). routine swaps not string or pointer-to-string, swaps integers @ target addresses. since integer is, according result, 4 bytes long on op's machine, code "swaps" first 4 bytes of target strings.


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