如何在Unix平台上的文件中grep标签(\t) ?


当前回答

在表达式中插入制表符的另一种方法是使用Bash中不太为人所知的$'\t'引号:

grep $'foo\tbar'        # matches eg. 'foo<tab>bar'

(注意,如果你匹配固定字符串,你可以使用-F模式。)

有时使用变量可以使符号更易于阅读和管理:

tab=$'\t'               # `tab=$(printf '\t')` in POSIX
id='[[:digit:]]\+'
name='[[:alpha:]_][[:alnum:]_-]*'
grep "$name$tab$id"     # matches eg. `bob2<tab>323`

其他回答

您也可以使用Perl一行程序来代替grep响应。grep - p:

perl -ne 'print if /\t/' FILENAME

我用ksh

grep "[^I]" testfile

下面是问Ubuntu的答案:

告诉grep使用由Perl定义的正则表达式(Perl拥有 \t as tab): grep -P "\t" <文件名称> . grep "\t" <文件名称> . grep "\t 使用文字制表符: grep "^V<tab>" <文件名> . grep "^V<tab> 使用printf打印制表符: Grep "$(printf '\t')"<文件名>

你可能想使用grep "$(echo -e '\t')"

唯一的要求是echo能够解释反斜杠转义。

These alternative binary identification methods are totally functional. And, I really like the one's using awk, as I couldn't quite remember the syntaxic use with single binary chars. However, it should also be possible to assign a shell variable a value in a POSIX portable fashion (i.e. TAB=echo "@" | tr "\100" "\011"), and then employ it from there everywhere, in a POSIX portable fashion; as well (i.e grep "$TAB" filename). While this solution works well with TAB, it will also work well other binary chars, when another desired binary value is used in the assignment (instead of the value for the TAB character to 'tr').