标题: How do I get the exit code of cmd1 in cmd1|cmd2|cmd3 请高手说明一下 [打印本页] 作者: johndoe 时间: 2006-02-14 15:48 标题: How do I get the exit code of cmd1 in cmd1|cmd2|cmd3 请高手说明一下 我查了这个在sh中的一个说明..但是我不是太明白.
How do I get the exit code of cmd1 in cmd1|cmd2|cmd3
exec 3>&1
eval `
# now, inside the `...`, fd4 goes to the pipe
# whose other end is read and passed to eval;
# fd1 is the normal standard output preserved
# the line before with exec 3>&1
exec 4>&1 >&3 3>&-
{
cmd1 4>&-; echo "ec1=$?;" >&4
} | {
cmd2 4>&-; echo "ec2=$?;" >&4
} | cmd3
echo "ec3=$?;" >&4
`
请问 exec 3>&1, exec 4>&1 >&3 3>&1 中的意思是什么？完全看不明白..请高手指点一下..多谢