[root@gateway root]# gcc -o captest captest.c
/tmp/ccIZi2YV.o(.text+0x47): In function `main':
: undefined reference to `snd_pcm_open'
/tmp/ccIZi2YV.o(.text+0x5e): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x96): In function `main':
: undefined reference to `snd_pcm_hw_params_malloc'
/tmp/ccIZi2YV.o(.text+0xb0): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0xe5): In function `main':
: undefined reference to `snd_pcm_hw_params_any'
/tmp/ccIZi2YV.o(.text+0xff): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x136): In function `main':
: undefined reference to `snd_pcm_hw_params_set_access'
/tmp/ccIZi2YV.o(.text+0x150): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x187): In function `main':
: undefined reference to `snd_pcm_hw_params_set_format'
/tmp/ccIZi2YV.o(.text+0x1a1): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x1e6): In function `main':
: undefined reference to `snd_pcm_hw_params_set_rate_near'
/tmp/ccIZi2YV.o(.text+0x200): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x24d): In function `main':
: undefined reference to `snd_pcm_hw_params_set_channels'
/tmp/ccIZi2YV.o(.text+0x267): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x29c): In function `main':
: undefined reference to `snd_pcm_hw_params'
/tmp/ccIZi2YV.o(.text+0x2b6): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x2e5): In function `main':
: undefined reference to `snd_pcm_hw_params_free'
/tmp/ccIZi2YV.o(.text+0x2f6): In function `main':
: undefined reference to `snd_pcm_prepare'
/tmp/ccIZi2YV.o(.text+0x310): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x35a): In function `main':
: undefined reference to `snd_pcm_readi'
/tmp/ccIZi2YV.o(.text+0x378): In function `main':
: undefined reference to `snd_strerror'
/tmp/ccIZi2YV.o(.text+0x3ae): In function `main':
: undefined reference to `snd_pcm_close'
collect2: ld returned 1 exit status