功能:实现shell字符串连接功能
a=0 s1=test. s2=.wav s3=.mp3 s4=0 s5=00 str="sox ./${s1}${a}${s2} ./${a}${s3}" ./tts -c bcgirl.0.0.4.bin -b 1 -i input.txt -s 1.0 -speed 1.0 $str rm ./*.wav