c - App crashes while finding elements in array -

the input file in.wav. have read chunks (succeeded) , read samples normalize audio file...

the problem crashes while trying fing max , min values of .wav file's samples. find minimum value , maximum 1 in array, it crashes...

tell me wrong, please. see no reason of such kind of behaviour.

here code:

#include <stdio.h> #include <stdlib.h> #include "main.h" #define hdr_size 64  typedef struct fmt {     char        subchunk1id[4];     int         subchunk1size;     short int   audioformat;     short int   numchannels;     int         samplerate;     int         byterate;     short int   blockalign;     short int   bitspersample;  } fmt;  typedef struct data {     char        subchunk2id[4];     int         subchunk2size;     int         data[441000];  } data;  typedef struct header {     char        chunkid[4];     int         chunksize;     char        format[4];     fmt         s1;     data        s2; } header;    int main() {     file *input = fopen( "in.wav", "rb");   /// namein      if(input == null)     {         printf("unable open wave file (input)\n");         exit(exit_failure);     }      file *output = fopen( "out.wav", "wb"); /// nameout     header hdr;       fread(&hdr, sizeof(char), hdr_size, input);      /* note: chunks has been copied successfully. */       char *ptr;       long n = hdr.s2.subchunk2size;       /// copying samples...     ptr = malloc(sizeof(n));      fread( ptr, 1, n, input );          int min = ptr[0], max = ptr[0], i;      /* problem here: */     ( = 0; <= n; i++ )  // finding 'max' , 'min'.         {             if ( ptr[i] < min )                     min = ptr[i];             if ( ptr[i] > max )                  max = ptr[i];     }      printf("> > >%d__%d\n", min, max);    // displaying of 'min' , 'max'.      fclose(input);     fclose(output);      return 0; } 

why behaves strange?

problem in (at least)

ptr = malloc(sizeof(n)); 

because sizeof(n) 4, sizeof(n) equals sizeof(long). allocated 4 bytes ptr.

the solution of problem following:

ptr = malloc(n);  /* allocate size of 'n' (27164102 bytes),    not data type size (4 bytes). */