/* * FILE: sine.c *   BY: Christopher Lee Fraley (cf0v@spice.cs.cmu.edu) * DESC: Creates sine waves of given period, amplitude, and length. * * 1.0 ( 1-JUN-88) - created. (cf0v) * 2.0 ( 5-JUL-88) - converted to binary sound file format. (cf0v) *//* * sine <amplitude> <period> <length> [-outfile] *    Outputs integer sine wave of maximum <amplitude>, with <period> * samples per period, and <length> number of periods to stdout. Illegal * arguments cause the defaults 32767, 20, and 3 to be used, respectively. * If the flag "-outfile" is present, the output is in binary format to the * named file.  If the flag is ommitted, the output is to stdout, and is in * ascii format, one number per line. */#include <stdio.h>#include <math.h>#include "stdefs.h"#define PERMS 0644      /* -rw-r--r-- */fails(s, s2)char *s, *s2;{   fprintf(stderr, s, s2);   exit(1);}main (argc,argv)int argc;char *argv[];{   double Amp, Samps, Perds;   int i;   if (argc!=4  &&  argc!=5)      fails("format is 'sine %s'\n",         "<amplitude> <samples-per-period> <#-of-periods> [-outfile]");   if (!sscanf(*++argv, "%lf", &Amp))      Amp = 32767.0;   if (!sscanf(*++argv, "%lf", &Samps))      Samps = 20.0;   if (!sscanf(*++argv, "%lf", &Perds))      Perds = 3.0;   if (argc==5)      {      int fout;      HWORD *Data, *ptr;      unsigned int outLen, len;      if (NULL > (fout = creat(*++argv+1, PERMS)))        fails("could not create <outfile> '%s'\n", *argv+1);      outLen = Samps*Perds*sizeof(HWORD);      ptr = Data = (HWORD *)malloc(outLen);      if (NULL == Data)         fails("could not allocate enough memory for output", "");      for (i=0; i<(Samps*Perds); i++)         *ptr++ = (HWORD) (sin(2*PI*i/Samps) * Amp);      len = write(fout, (char *)Data, outLen);      if (len != outLen)         fails("incorrect number of bytes written", "");      }   else     {     for (i=0; i<(Samps*Perds); i++)        printf("%d\n", (int)(sin(2*PI*i/Samps)*Amp));     }}