我正在尝试将包含c1t1的行的“FS”类型从ufs更改为ext2，并在这些行的任何位置将c1t1更改为c1t2。这就是文件的样子：
#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
#/dev/dsk/c1d0s2 /dev/rdsk/c1d0s2 /usr ufs 1 yes -
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s1 - - swap - no -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no -
/dev/dsk/c0t0d0s6 /dev/rdsk/c0t0d0s6 /usr ufs 1 no -
/dev/dsk/c0t0d0s4 /dev/rdsk/c0t0d0s4 /var ufs 1 no -
/dev/dsk/c0t0d0s5 /dev/rdsk/c0t0d0s5 /local ufs 2 yes -
/dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s3 /usr/openwin ufs 2 yes -
/dev/dsk/c1t0d0s0 /dev/rdsk/c1t0d0s0 /opt ufs 3 yes -
/dev/dsk/c1t0d0s3 /dev/rdsk/c1t0d0s3 /export/user1 ufs 3 yes nosuid
/dev/dsk/c1t1d0s0 /dev/rdsk/c1t1d0s0 /usr/local ufs 3 yes -
/dev/dsk/c1t1d0s3 /dev/rdsk/c1t1d0s3 /export/user3 ufs 3 yes nosuid
/dev/dsk/c2t0d0s0 /dev/rdsk/c2t0d0s0 /export/home ufs 4 yes nosuid
/dev/dsk/c2t0d0s3 /dev/rdsk/c2t0d0s3 /casa6 ufs 4 yes -
/dev/dsk/c2t3d0s0 /dev/rdsk/c2t3d0s0 /export/user2 ufs 5 yes nosuid
/dev/dsk/c2t3d0s3 /dev/rdsk/c2t3d0s3 /stage ufs 5 yes -
# ringer.cs.utsa.edu:/usr/local/news - /usr/local/news nfs - yes retry=10
ringer.cs.utsa.edu:/var/mail - /var/mail nfs - yes retry=10,actimeo=0
#ringer.cs.utsa.edu:/var/spool/news - /var/spool/news nfs - yes retry=10
#ringer.cs.utsa.edu:/answerbook - /answerbook nfs - yes retry=10
swap - /tmp tmpfs - yes -
这就是我所能想到的：
s/(^\/dev\/dsk\/c1t1.*)ufs(.*$)/$1ext2$2/
答案 0 :(得分：3)
当语法有点混乱时，有时候是时候使用awk：
awk '$1~/c1t1/ {$4="ext2"; sub("c1t1","c1t2",$0)}1' file
$1~/c1t1/检查第一个字段是否包含c1t1。如果是，请执行{}。$4="ext2"将第4个字段设为“ext2”。sub("c1t1","c1t2",$0)将整个行c1t1中的所有c1t2替换为$0。1打印所有行。您可以执行它并重定向到另一个文件：awk ... file > new_file。
$ awk '$1~/c1t1/ {$4="ext2"; sub("c1t1","c1t2",$0)}1' file
#device device mount FS fsck mount mount
#to mount to fsck point type pass at boot options
#
#/dev/dsk/c1d0s2 /dev/rdsk/c1d0s2 /usr ufs 1 yes -
fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s1 - - swap - no -
/dev/dsk/c0t0d0s0 /dev/rdsk/c0t0d0s0 / ufs 1 no -
/dev/dsk/c0t0d0s6 /dev/rdsk/c0t0d0s6 /usr ufs 1 no -
/dev/dsk/c0t0d0s4 /dev/rdsk/c0t0d0s4 /var ufs 1 no -
/dev/dsk/c0t0d0s5 /dev/rdsk/c0t0d0s5 /local ufs 2 yes -
/dev/dsk/c0t0d0s3 /dev/rdsk/c0t0d0s3 /usr/openwin ufs 2 yes -
/dev/dsk/c1t0d0s0 /dev/rdsk/c1t0d0s0 /opt ufs 3 yes -
/dev/dsk/c1t0d0s3 /dev/rdsk/c1t0d0s3 /export/user1 ufs 3 yes nosuid
/dev/dsk/c1t2d0s0 /dev/rdsk/c1t1d0s0 /usr/local ext2 3 yes -
/dev/dsk/c1t2d0s3 /dev/rdsk/c1t1d0s3 /export/user3 ext2 3 yes nosuid
/dev/dsk/c2t0d0s0 /dev/rdsk/c2t0d0s0 /export/home ufs 4 yes nosuid
/dev/dsk/c2t0d0s3 /dev/rdsk/c2t0d0s3 /casa6 ufs 4 yes -
/dev/dsk/c2t3d0s0 /dev/rdsk/c2t3d0s0 /export/user2 ufs 5 yes nosuid
/dev/dsk/c2t3d0s3 /dev/rdsk/c2t3d0s3 /stage ufs 5 yes -
# ringer.cs.utsa.edu:/usr/local/news - /usr/local/news nfs - yes retry=10
ringer.cs.utsa.edu:/var/mail - /var/mail nfs - yes retry=10,actimeo=0
#ringer.cs.utsa.edu:/var/spool/news - /var/spool/news nfs - yes retry=10
#ringer.cs.utsa.edu:/answerbook - /answerbook nfs - yes retry=10
swap - /tmp tmpfs - yes -
答案 1 :(得分：1)
您的搜索可能会受益于捕获和替换：
sed -e 's/^\(.*dsk\/\)c1t1\(.*\)ufs\(.*\)$/\1c1t2\2ext2\3/g' some_file
它不具有可读性，还有其他方法可以做到，但\( \)捕获了一些内容。在上面的例子中，我捕获了三件事，当我想将它们转储回来时，我会按照以下方式（按捕获顺序）引用它们：
\1 \2 \3