sed awk用模式匹配替換行

Question

使用awk或sed，如何在模式匹配后替換每一行？ 模式將始終以S：\\開頭，我需要從S：\\〜到整行都顯示在空白行之前的下一行中。

我有這樣的輸入：

S:\dir1\subfolder1longsubf
abcdefg
1234567
permissions

S:\dir2\verylongsub
some random string
some random string

S:\dir3
some random string
some random string

S:\dir4\sub2\sub3
some random string
some random string
some random string

我需要這樣的輸出：

S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf

S:\dir2\verylongsub
S:\dir2\verylongsub
S:\dir2\verylongsub

S:\dir3
S:\dir3
S:\dir3

S:\dir4\sub2\sub3
S:\dir4\sub2\sub3
S:\dir4\sub2\sub3
S:\dir4\sub2\sub3

Answer 1

我會用awk ：

awk '/^S/ {line=$0} {print NF?line:""}' file

這將存儲以S開頭的行。 然后，它打印此存儲的值，或者如果該行為空，則打印一個空行。

測試

$ awk '/^S/ {line=$0} {print NF?line:""}' file
S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf
S:\dir1\subfolder1longsubf

S:\dir2\verylongsub
S:\dir2\verylongsub
S:\dir2\verylongsub

S:\dir3
S:\dir3
S:\dir3

S:\dir4\sub2\sub3
S:\dir4\sub2\sub3
S:\dir4\sub2\sub3
S:\dir4\sub2\sub3

Answer 2

使用GNU sed：

sed  '/^S:/{h};/^[^S]/{g}' file