给定这个文件:
$ cat file
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lima mike
november oscar papa quebec romeo sierra tango
uniform_victor_whiskey_xray yankee zulu
我想在70岁的时候努力突破,但我也想努力补充。我尝试了“折叠”,但它没有重新填充:
$ fold -w 70 file
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
a mike
november oscar papa quebec romeo sierra tango
uniform_victor_whiskey_xray yankee zulu
“fmt”会重新填充,但我只能让它在空格上中断,所以不能保证正好 70 换行:
$ fmt file
alfa bravo charlie delta echo foxtrot golf hotel india juliet
kilo lima mike november oscar papa quebec romeo sierra tango
uniform_victor_whiskey_xray yankee zulu
我尝试了“pr”,但它似乎只是截断了该行而不换行:
$ pr -t -W 70 file
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
november oscar papa quebec romeo sierra tango
uniform_victor_whiskey_xray yankee zulu
也许这些命令有一些我缺少的选项,或者可能是 Awk 或 Sed 解决方案。我宁愿避免较重的解决方案(Perl PHP Ruby)。
答案1
使用 sed
使用 GNU sed:
$ sed -zE 's/\n/ /g; s/.{70}/&\n/g; s/$/\n/' file
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
a mike november oscar papa quebec romeo sierra tango uniform_victor_wh
iskey_xray yankee zulu
对于任何 POSIX sed:
sed -zE 'H;1h;$!d;x; s/\n/ /g; s/.{70}/&\n/g; s/$/\n/' file
使用 awk
$ awk '{r=(length(r)?r" "$0:$0); while(length(r)>70){print substr(r,1,70); r=substr(r,71)}} END{print r}' file
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
a mike november oscar papa quebec romeo sierra tango uniform_victor_wh
iskey_xray yankee zulu
与 tr 和折叠
$ tr '\n' ' ' <file | fold -w 70
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
a mike november oscar papa quebec romeo sierra tango uniform_victor_wh
iskey_xray yankee zulu
上面的代码不会产生尾随换行符,但我们可以根据需要添加一个换行符echo ""
:
tr '\n' ' ' <file | fold -w 70; echo
答案2
这并不适用于所有情况,但它应该涵盖大多数用例:
$ fmt -w 2500 file | fold -w 70
alfa bravo charlie delta echo foxtrot golf hotel india juliet kilo lim
a mike november oscar papa quebec romeo sierra tango uniform_victor_wh
iskey_xray yankee zulu