linux - 使用 "while read"和 "for i in"导致不明确的重定向

Question

# while read a b ; do echo $a $b ; done < `for i in \`cat users.txt\` ; do PHPVER=\`selectorctl --user-current --user=$i\` ; echo $i $PHPVER ; done | awk '{print $1, $2}' | sed 's/native/5.3/g'`

-bash: `for i in \`cat users.txt\` ; do PHPVER=\`selectorctl --user-current --user=$i\` ; echo $i $PHPVER ; done | awk '{print $1, $2}' | sed 's/native/5.3/g'`: ambiguous redirect

如果删除 while read 语句，输出为:

# for i in `cat users.txt` ; do PHPVER=`selectorctl --user-current --user=$i` ; echo $i $PHPVER ; done | awk '{print $1, $2}' | sed 's/native/5.3/g'

user1 5.4
user2 5.4
user3 5.3

所以我需要将这两列转换为一个变量，这样我就可以在这样的命令中运行它们:

# selectorctl --set-user-current=$b --user=$a

但是，当我添加 while read 语句时，它会引发不明确的重定向

Answer 1

确实不清楚你想做什么。您可能想做类似的事情

while read -r user; do
    read phpver rest < <(selectorctl --user-current --user="$user")
    output="$user $phpver"
    echo "${output//native/5.3}"
done < users.txt

Don't use for to read lines from a file .