如何在Unix平台上的文件中grep标签(\t) ?


当前回答

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').

其他回答

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`

grep "$(printf '\t')"在Mac OS X上为我工作

使用gawk,将字段分隔符设置为TAB (\t)并检查字段的数量。如果多于1,则有/有制表符

awk -F"\t" 'NF>1' file

我从来没有设法使“\t”元字符与grep一起工作。 然而,我发现了两个替代方案:

使用<Ctrl-V> <TAB>(按Ctrl-V然后输入TAB) 使用awk: foo | awk '/\t/'

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