在这种特定情况下，您可以在不使用非贪婪正则表达式的情况下完成工作。

试试这个非贪婪的正则表达式[^/]*来代替。*?：

sed 's|\(http://[^/]*/\).*|\1|g'

在sed中模拟惰性(非贪婪)量词

以及所有其他正则表达式口味!

Finding first occurrence of an expression: POSIX ERE (using -r option) Regex: (EXPRESSION).*|. Sed: sed -r ‍'s/(EXPRESSION).*|./\1/g' # Global `g` modifier should be on Example (finding first sequence of digits) Live demo: $ sed -r 's/([0-9]+).*|./\1/g' <<< 'foo 12 bar 34' 12 How does it work? This regex benefits from an alternation |. At each position engine tries to pick the longest match (this is a POSIX standard which is followed by couple of other engines as well) which means it goes with . until a match is found for ([0-9]+).*. But order is important too. Since global flag is set, engine tries to continue matching character by character up to the end of input string or our target. As soon as the first and only capturing group of left side of alternation is matched (EXPRESSION) rest of line is consumed immediately as well .*. We now hold our value in the first capturing group. POSIX BRE Regex: \(\(\(EXPRESSION\).*\)*.\)* Sed: sed 's/\(\(\(EXPRESSION\).*\)*.\)*/\3/' Example (finding first sequence of digits): $ sed 's/\(\(\([0-9]\{1,\}\).*\)*.\)*/\3/' <<< 'foo 12 bar 34' 12 This one is like ERE version but with no alternation involved. That's all. At each single position engine tries to match a digit. If it is found, other following digits are consumed and captured and the rest of line is matched immediately otherwise since * means more or zero it skips over second capturing group \(\([0-9]\{1,\}\).*\)* and arrives at a dot . to match a single character and this process continues. Finding first occurrence of a delimited expression: This approach will match the very first occurrence of a string that is delimited. We can call it a block of string. sed 's/\(END-DELIMITER-EXPRESSION\).*/\1/; \ s/\(\(START-DELIMITER-EXPRESSION.*\)*.\)*/\1/g' Input string: foobar start block #1 end barfoo start block #2 end -EDE: end -SDE: start $ sed 's/\(end\).*/\1/; s/\(\(start.*\)*.\)*/\1/g' Output: start block #1 end First regex \(end\).* matches and captures first end delimiter end and substitues all match with recent captured characters which is the end delimiter. At this stage our output is: foobar start block #1 end. Then the result is passed to second regex \(\(start.*\)*.\)* that is same as POSIX BRE version above. It matches a single character if start delimiter start is not matched otherwise it matches and captures the start delimiter and matches the rest of characters.

直接回答你的问题

使用方法#2(带分隔符的表达式)，你应该选择两个合适的表达式:

艾德:[^]\ / SDE: http:

用法:

$ sed 's/\([^:/]\/\).*/\1/g; s/\(\(http:.*\)*.\)*/\1/' <<< 'http://www.suepearson.co.uk/product/174/71/3816/'

输出:

http://www.suepearson.co.uk/

注意:对于相同的分隔符，这将不起作用。

echo "/home/one/two/three/myfile.txt" | sed 's|\(.*\)/.*|\1|'

别麻烦了，我在另一个论坛上看到的:)

@Daniel H(关于你对andcoz的回答的评论，虽然是很久以前的事了):删除后面的零

s,([[:digit:]]\.[[:digit:]]*[1-9])[0]*$,\1,g

这是关于清楚地定义匹配条件……

以下是你可以用两步方法和awk完成的事情:

A=http://www.suepearson.co.uk/product/174/71/3816/  
echo $A|awk '  
{  
  var=gensub(///,"||",3,$0) ;  
  sub(/\|\|.*/,"",var);  
  print var  
}'  

输出: http://www.suepearson.co.uk

希望有帮助!

这可以使用cut:

echo "http://www.suepearson.co.uk/product/174/71/3816/" | cut -d'/' -f1-3