如何使用正则表达式查找至少两次相同单词的行？
我试过了：
egrep '\w{2,}\1' file
但终端给了我错误：
egrep：无效的反向引用号
答案 0 :(得分：3)
目前的正则表达式有几个问题。
\b word boundaries以限制左侧和右侧的字词。.*以匹配any amount之间的any characters。echo "ABC foo ABC bar" | egrep '\b(\w{2,})\b.*\b\1\b'
ABC foo ABC吧
echo "ABC foo ABCD bar" | egrep '\b(\w{2,})\b.*\b\1\b'
false
See demo at regex101。如果需要，请使用egrep -o - 仅匹配来提取相关部分
您可以使用.*? -P - perl-regexp 进一步使用(function () {
var v = "1.3.2";
if (window.jQuery === undefined || window.jQuery.fn.jquery < v) {
var done = false;
var script = document.createElement("script");
script.src = "http://ajax.googleapis.com/ajax/libs/jquery/" + v + "/jquery.min.js";
script.onload = script.onreadystatechange = function () {
if (!done && (!this.readyState || this.readyState == "loaded" || this.readyState == "complete")) {
done = true;
initMyBookmarklet();
}
};
document.getElementsByTagName("head")[0].appendChild(script);
} else {
initMyBookmarklet();
}
function initMyBookmarklet() {
(window.myBookmarklet = function () {
function getSelText() {
var s = '';
if (window.getSelection) {
s = window.getSelection();
} else if (document.getSelection) {
s = document.getSelection();
} else if (document.selection) {
s = document.selection.createRange().text;
}
return s;
}
if ($("#wikiframe").length == 0) {
var s = "";
s = getSelText();
if (s == "") {
var s = prompt("Forget something?");
}
if ((s != "") && (s != null)) {
$("body").append("<div id='wikiframe'>
<div id='wikiframe_veil' style=''>
<p>Loading...</p>
</div>
<iframe src='http://en.wikipedia.org/w/index.php?&search=" + s + "' onload=" $('#wikiframe iframe').slideDown(500); ">Enable iFrames.</iframe>
<style type='text/css'>
#wikiframe_veil { display: none; position: fixed; width: 100%; height: 100%; top: 0; left: 0; background-color: rgba(255,255,255,.25); cursor: pointer; z-index: 900; }
#wikiframe_veil p { color: black; font: normal normal bold 20px/20px Helvetica, sans-serif; position: absolute; top: 50%; left: 50%; width: 10em; margin: -10px auto 0 -5em; text-align: center; }
#wikiframe iframe { display: none; position: fixed; top: 10%; left: 10%; width: 80%; height: 80%; z-index: 999; border: 10px solid rgba(0,0,0,.5); margin: -5px 0 0 -5px; }
</style>
</div> "); //the append tag ends here, but the browser is showing syntax error on appending multiple HTML codes
$("#wikiframe_veil").fadeIn(750);
}
} else {
$("#wikiframe_veil").fadeOut(750);
$("#wikiframe iframe").slideUp(500);
setTimeout("$('#wikiframe').remove()", 750);
}
$("#wikiframe_veil").click(function (event) {
$("#wikiframe_veil").fadeOut(750);
$("#wikiframe iframe").slideUp(500);
setTimeout("$('#wikiframe').remove()", 750);
});
})();
}
})();
lazy点。
答案 1 :(得分：1)
请改为尝试：
egrep '(\w{2,}).*\1' file
如果您没有捕获组（(...)），则没有任何反向引用。
以下是一个例子：
$ cat file
this line has the same word twice word
this line does not
this is this and that is that
$ egrep '(\w{2,}).*\1' file
this line has the same word twice word
this is this and that is that