0 个或多个空格的 grep 正则表达式答案

【问题标题】：grep regex of 0 or many spaces0 个或多个空格的 grep 正则表达式
【发布时间】：2015-01-20 09:52:48
【问题描述】：

我想根据正则表达式对文件进行 grep。

在正则表达式中，我想在空格或无空格上进行比较，所以我尝试了以下表达式：/ {0,}/ 但它不起作用。

在我的整个正则表达式之后

cat test.txt  | grep "\"cache_changes\":/ {0,}/\"xax.yby.zcz[ \"]"

我该怎么做？

在我的文件 test.txt 之后：

{ "nbr": "01", "parameter": "toto.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes":"xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "02", "parameter": "toto.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz xa2x.yb2y.zc2z" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "03", "parameter": "toto.aaa.2.bbb", "value": "45", "notification": "0", "cache_changes": "xa2x.yb2y.zc2z xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "04", "parameter": "toto.ffff.3.bbb", "value": "45", "notification": "0", "cache_changes": "xa2x.yb2y.zc2z xax.yby.zcz xa3x.yb3y.zc3z" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "05", "parameter": "titi.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes": "xdx.yey.zfz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "06", "parameter": "titi.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xdx.yey.zfz xd2x.ye2y.zf2z" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "07", "parameter": "titi.aaa.2.bbb", "value": "45", "notification": "0", "cache_changes": "xd2x.ye2y.zf2z xdx.yey.zfz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "08", "parameter": "titi.ffff.3.bbb", "value": "45", "notification": "0", "cache_changes": "xd2x.ye2y.zf2z xdx.yey.zfz xd3x.ye3y.zf3z" "set_cmd": "any_f xax.yby.zcz $val" }

想要的输出是：

{ "nbr": "01", "parameter": "toto.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes":"xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "02", "parameter": "toto.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz xa2x.yb2y.zc2z" "set_cmd": "any_f xax.yby.zcz $val" }

【问题讨论】：

请在问题中包含您想要的输出。解析 JSON，不要使用grep，使用jq。

标签： regex linux bash shell grep

【解决方案1】：

试试这个命令：

grep "\"cache_changes\": *\"xax.yby.zcz[ \"]" test.txt

使用问题中提供的测试文件，我得到的是：

{ "nbr": "01", "parameter": "toto.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "02", "parameter": "toto.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz xa2x.yb2y.zc2z" "set_cmd": "any_f xax.yby.zcz $val" }

【讨论】：

你不应该将cat与可以读取数据的程序一起使用，比如grep。

【解决方案2】：

使用*（重复前一个标记零次或多次）而不是重复量词{}

$ grep "\"cache_changes\": *\"xax.yby.zcz[ \"]" file
{ "nbr": "01", "parameter": "toto.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "02", "parameter": "toto.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz xa2x.yb2y.zc2z" "set_cmd": "any_f xax.yby.zcz $val" }

如果你真的想使用那个量词，你需要转义大括号，比如

$ grep '"cache_changes": \{0,\}"xax.yby.zcz[ "]' file
{ "nbr": "01", "parameter": "toto.aaa.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz" "set_cmd": "any_f xax.yby.zcz $val" }
{ "nbr": "02", "parameter": "toto.eeee.1.bbb", "value": "45", "notification": "0", "cache_changes": "xax.yby.zcz xa2x.yb2y.zc2z" "set_cmd": "any_f xax.yby.zcz $val" }

【讨论】：

什么意思？我认为问题主要出在您的命令本身。我只是用*替换你输入中的{0,}
grep '"cache_changes":/ \{0,\}/"xax.yby.zcz[ "]' file
我会把我的文件内容放在问题里，你可以试试你的命令，你会发现什么都不会显示
@MOHAMED "xax之前没有正斜杠