linux shell 里面，真值为0，假值为非0

真是个神奇的现象～

linux c programming 里 有这么个程序

#!/bin/shyes_or_no() {  echo "Is your name $* ?"  while true  do    echo -n "Enter yes or no: "    read x    case "$x" in      y | yes ) return 0;;      n | no )  return 1;;      * )       echo "Answer yes or no"    esac  done}echo "Original parameters are $*"if yes_or_no "$1" then  echo "Hi $1, nice name"else  echo "Never mind"fiexit 0

执行后的结果很有意思

$ ./func.sh pp hh
original parameters are pp hh
Is this your name pp ?
Enter yes or no:y
0 Hi pp, nice name

$ ./func.sh pp hh
original parameters are pp hh
Is this your name pp ?
Enter yes or no:n
1 Never mind

return值为0 进入then 1 进入else

也就是说在shell 里，真值为0 假值为非0

跟c正好相反