通过shell脚本将/etc/fstab文件中的选项noexec替换为exec

Question

只有noexec到exec的/tmp选项应该更改。noexec到exec的/var/tmp选项不应更改。

/etc/fstab 的内容

UUID=f229a689-a31e-4f1a-a823-9a69ee6ec558       /         xfs     defaults        0 0
UUID=eeb1df48-c9b0-408f-a693-38e2f7f80895       /boot         xfs     defaults        1 2
UUID=b41e6ef9-c638-4084-8a7e-26ecd2964893       swap      swap    defaults        0 0
UUID=79aa80a1-fa97-4fe1-a92d-eadf79721204       /var         xfs     defaults        1 2
UUID=644be3d0-433c-4ed5-bf12-7f61d5b99860       /tmp         xfs     defaults,nodev,nosuid,noexec        1 2
UUID=decda446-34ac-45b6-826c-ae3f090ed717       /var/log         xfs     defaults        1 2
UUID=a74170bc-0309-4b3b-862e-722fb7a6882d       /var/tmp         xfs     defaults,nodev,nosuid,noexec        1 2

Answer 1

使用awk:

$ cat 1.awk
$2=="/tmp"  { n=split($4,a,",");
str=""
for (i=1; i <= n; i++ ) {
if (a[i] != "noexec") {
if (length(str))
str=str","
str=str""a[i]
}
}
$4=str; print }
$2 != "/tmp" { print }
$ awk -f 1.awk fstab
UUID=f229a689-a31e-4f1a-a823-9a69ee6ec558       /         xfs     defaults        0 0
UUID=eeb1df48-c9b0-408f-a693-38e2f7f80895       /boot         xfs     defaults        1 2
UUID=b41e6ef9-c638-4084-8a7e-26ecd2964893       swap      swap    defaults        0 0
UUID=79aa80a1-fa97-4fe1-a92d-eadf79721204       /var         xfs     defaults        1 2
UUID=644be3d0-433c-4ed5-bf12-7f61d5b99860 /tmp xfs defaults,nodev,nosuid 1 2
UUID=decda446-34ac-45b6-826c-ae3f090ed717       /var/log         xfs     defaults        1 2
UUID=a74170bc-0309-4b3b-862e-722fb7a6882d       /var/tmp         xfs     defaults,nodev,nosuid,noexec        1 2

注意，使用printf可以容易地改善修改行中的场的对准。我无法判断您在各个字段之间使用的是制表符还是空格。