alsa cap test

/* to compile: * gcc -lasound alsa_test_cap.c -o alsa_test_cap * * to run * ./alsa_test_cap default */#include <stdio.h>	#include <stdlib.h>	#include <alsa/asoundlib.h>	      	main (int argc, char *argv[])	{		int i;		int err;		short buf[128];		snd_pcm_t *capture_handle;		snd_pcm_hw_params_t *hw_params;        int exact_rate = 44100;        int cp=0;        if (argc!=2) {          printf("provide thing\n");          exit(0);        }        printf("cp %i\n", cp++); fflush(stdout);			if ((err = snd_pcm_open (&capture_handle, argv[1], SND_PCM_STREAM_CAPTURE, 0)) < 0) {			fprintf (stderr, "cannot open audio device %s (%s)\n", 				 argv[1],				 snd_strerror (err));			exit (1);		}        //printf("..\n"); fflush(stdout); snd_pcm_close(capture_handle);        printf("cp %i\n", cp++); fflush(stdout);		   		if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {			fprintf (stderr, "cannot allocate hardware parameter structure (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("cp %i\n", cp++); fflush(stdout);				 		if ((err = snd_pcm_hw_params_any (capture_handle, hw_params)) < 0) {			fprintf (stderr, "cannot initialize hardware parameter structure (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("cp %i\n", cp++); fflush(stdout);			if ((err = snd_pcm_hw_params_set_access (capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {			fprintf (stderr, "cannot set access type (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("cp %i\n", cp++); fflush(stdout);			if ((err = snd_pcm_hw_params_set_format (capture_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {			fprintf (stderr, "cannot set sample format (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("cp %i\n", cp++); fflush(stdout);			if ((err = snd_pcm_hw_params_set_rate_near (capture_handle, hw_params, &exact_rate, 0)) < 0) {			fprintf (stderr, "cannot set sample rate (%s)\n",				 snd_strerror (err));			exit (1);		}	        printf("cp %i\n", cp++); fflush(stdout);		if ((err = snd_pcm_hw_params_set_channels (capture_handle, hw_params, 2)) < 0) {			fprintf (stderr, "cannot set channel count (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("cp %i\n", cp++); fflush(stdout);			if ((err = snd_pcm_hw_params (capture_handle, hw_params)) < 0) {			fprintf (stderr, "cannot set parameters (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("...\n");        printf("cp %i\n", cp++); fflush(stdout);			snd_pcm_hw_params_free (hw_params);        printf("...\n"); fflush(stdout);			if ((err = snd_pcm_prepare (capture_handle)) < 0) {			fprintf (stderr, "cannot prepare audio interface for use (%s)\n",				 snd_strerror (err));			exit (1);		}        printf("....\n"); fflush(stdout);			for (i = 0; i < 10; ++i) {			if ((err = snd_pcm_readi (capture_handle, buf, 128)) != 128) {				fprintf (stderr, "read from audio interface failed (%s)\n",					 snd_strerror (err));				exit (1);			}		}        printf(".....\n"); fflush(stdout);			snd_pcm_close (capture_handle);        printf("???\n"); fflush(stdout);		exit (0);	}