我有一堆不同类型的文件需要定期查看,它们的共同之处在于这些行有一堆key = value类型的字符串.所以类似于：
Version=2 Len=17 Hello Var=Howdy Other
我希望能够直接从awk中引用这些名称…所以类似于：
cat some_file | ... | awk '{print Var,$5}' # prints Howdy Other
我怎么能这样做呢？
你可以得到的最接近的是将每个行的变量解析为关联数组.也就是说,
awk '{ delete vars; for(i = 1; i <= NF; ++i) { n = index($i,"="); if(n) { vars[substr($i,1,n - 1)] = substr($i,n + 1) } } Var = vars["Var"] } { print Var,$5 }'
更可读：
{
delete vars; # clean up prevIoUs variable values
for(i = 1; i <= NF; ++i) { # walk through fields
n = index($i,"="); # search for =
if(n) { # if there is one:
# remember value by name. The reason I use
# substr over split is the possibility of
# something like Var=foo=bar=baz (that will
# be parsed into a variable Var with the
# value "foo=bar=baz" this way).
vars[substr($i,n + 1)
}
}
# if you know precisely what variable names you expect to get,you can
# assign to them here:
Var = vars["Var"]
Version = vars["Version"]
Len = vars["Len"]
}
{
print Var,$5 # then use them in the rest of the code
}
