AWK相当于LTRIM函数在c [英] awk equivalent of LTRIM function in C

问题描述

我只需要从一个字符串中删除前导零。我发现有一个像LTRIM没有内置的功能在C

I need to delete leading 0s only from a string. I found that there is no in-built function like LTRIM as in C.

我在想下面的awk脚本做到这一点：

I'm thinking of the below AWK script to do that:

awk -F"," 'BEGIN { a[$1] }
   for (v in a) {
       {if ($v == 0) {delete a[$v]; print a;} else exit;}
   }'

但你猜我没有正确声明数组，它抛出错误。对不起新AWK编程。你可以帮我把它在一起。

But guess I'm not declaring the array correctly, and it throws error. Sorry new to AWK programming. Can you please help me to put it together.

推荐答案

使用 AWK 的要求：

#!/usr/bin/awk -f
/^0$/   { print; next; }
/^0*[^0-9]/ { print; next; }
/^0/    { sub("^0+", "", $0); print; next; }
        { print $0; }

这提供了不修剪纯0到的空字符串的，以及避免的非数字的字段的（可能）不希望的修整。如果是后者实际上期望的行为，第二个模式/动作可以被注释掉。在这两种情况下，取代是去，因为加入了编号，以一个非数字字段将产生错误的方式。

This provides for not trimming a plain "0" to an empty string, as well as avoiding the (probably) unwanted trimming of non-numeric fields. If the latter is actually desired behavior, the second pattern/action can be commented out. In either case, substitution is the way to go, since adding a number to a non-numeric field will generate an error.

输入：

0
0x
0000x
00012

输出：

0
0x
0000x
12

输出微调非数字字段：

Output trimming non-numeric fields:

0
x
x
12

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