From 773790f4d732b098da0a4de7b1de6cc4dd2a2d18 Mon Sep 17 00:00:00 2001 From: geekpi Date: Mon, 13 Jan 2020 09:00:41 +0800 Subject: [PATCH] translating --- ...ic sequences with the Linux seq command.md | 165 ------------------ ...ic sequences with the Linux seq command.md | 153 ++++++++++++++++ 2 files changed, 153 insertions(+), 165 deletions(-) delete mode 100644 sources/tech/20200107 Generating numeric sequences with the Linux seq command.md create mode 100644 translated/tech/20200107 Generating numeric sequences with the Linux seq command.md diff --git a/sources/tech/20200107 Generating numeric sequences with the Linux seq command.md b/sources/tech/20200107 Generating numeric sequences with the Linux seq command.md deleted file mode 100644 index 7ae48a2785..0000000000 --- a/sources/tech/20200107 Generating numeric sequences with the Linux seq command.md +++ /dev/null @@ -1,165 +0,0 @@ -[#]: collector: (lujun9972) -[#]: translator: (geekpi) -[#]: reviewer: ( ) -[#]: publisher: ( ) -[#]: url: ( ) -[#]: subject: (Generating numeric sequences with the Linux seq command) -[#]: via: (https://www.networkworld.com/article/3511954/generating-numeric-sequences-with-the-linux-seq-command.html) -[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/) - -Generating numeric sequences with the Linux seq command -====== -The Linux seq command can generate lists of numbers and at lightning speed. It's easy to use and flexible, too. -[Jamie][1] [(CC BY 2.0)][2] - -One of the easiest ways to generate a list of numbers in Linux is to use the **seq** (sequence) command. In its simplest form, **seq** will take a single number and then list all the numbers from 1 to that number. For example: - -``` -$ seq 5 -1 -2 -3 -4 -5 -``` - -Unless directed otherwise, **seq** always starts with 1. You can start a sequence with a different number by inserting it before the final number. - -``` -$ seq 3 5 -3 -4 -5 -``` - -### Specifying an increment - -You can also specify an increment. Say you want to list multiples of 3. Specify your starting point (first 3 in this example), increment (second 3) and end point (18). - -[][3] - -BrandPost Sponsored by HPE - -[Take the Intelligent Route with Consumption-Based Storage][3] - -Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency. - -``` -$ seq 3 3 18 -3 -6 -9 -12 -15 -18 -``` - -You can elect to go from larger to smaller numbers by using a negative increment (i.e., a decrement). - -``` -$ seq 18 -3 3 -18 -15 -12 -9 -6 -3 -``` - -The **seq** command is also very fast. You can probably generate a list of a million numbers in under 10 seconds. - -Advertisement - -``` -$ time seq 1000000 -1 -2 -3 -… -… -999998 -999999 -1000000 - -real 0m9.290s <== 9+ seconds -user 0m0.020s -sys 0m0.899s -``` - -## Using a separator - -Another very useful option is to use a separator. Instead of listing a single number on each line, you can insert commas, colons or some other characters. The -s option followed by the character you wish to use. - -``` -$ seq -s: 3 3 18 -3:6:9:12:15:18 -``` - -In fact, if you simply want your numbers to be listed on a single line, you can use a blank as your separator in place of the default linefeed. - -**[ Also see [Invaluable tips and tricks for troubleshooting Linux][4]. ]** - -``` -$ seq -s' ' 3 3 18 -3 6 9 12 15 18 -``` - -### Getting to the math - -It may seem like a big leap to go from generating a sequence of numbers to doing math, but given the right separators, **seq** can easily prepare calculations that you can pass to **bc**. For example: - -``` -$ seq -s* 5 | bc -120 -``` - -What is going on in this command? Let’s take a look. First, **seq** is generating a list of numbers and using * as the separator. - -``` -$ seq -s* 5 -1*2*3*4*5 -``` - -It’s then passing the string to the calculator (**bc**) which promptly multiplies the numbers. And you can do a fairly extensive calculation in a fraction of a second. - -``` -$ time seq -s* 117 | bc -39699371608087208954019596294986306477904063601683223011297484643104\ -22041758630649341780708631240196854767624444057168110272995649603642\ -560353748940315749184568295424000000000000000000000000000 - -real 0m0.003s -user 0m0.004s -sys 0m0.000s -``` - -### Limitations - -You only get to choose one separator, so your calculations will be very limited. Use **bc** by itself for more complicated math. In addition, **seq** only works with numbers. To generate a sequence of single letters, use a command like this instead: - -``` -$ echo {a..g} -a b c d e f g -``` - -Join the Network World communities on [Facebook][5] and [LinkedIn][6] to comment on topics that are top of mind. - --------------------------------------------------------------------------------- - -via: https://www.networkworld.com/article/3511954/generating-numeric-sequences-with-the-linux-seq-command.html - -作者：[Sandra Henry-Stocker][a] -选题：[lujun9972][b] -译者：[译者ID](https://github.com/译者ID) -校对：[校对者ID](https://github.com/校对者ID) - -本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 - -[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/ -[b]: https://github.com/lujun9972 -[1]: https://creativecommons.org/licenses/by/2.0/ -[2]: https://creativecommons.org/licenses/by/2.0/legalcode -[3]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE21620&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage) -[4]: https://www.networkworld.com/article/3242170/linux/invaluable-tips-and-tricks-for-troubleshooting-linux.html -[5]: https://www.facebook.com/NetworkWorld/ -[6]: https://www.linkedin.com/company/network-world diff --git a/translated/tech/20200107 Generating numeric sequences with the Linux seq command.md b/translated/tech/20200107 Generating numeric sequences with the Linux seq command.md new file mode 100644 index 0000000000..0b12dfb508 --- /dev/null +++ b/translated/tech/20200107 Generating numeric sequences with the Linux seq command.md @@ -0,0 +1,153 @@ +[#]: collector: (lujun9972) +[#]: translator: (geekpi) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (Generating numeric sequences with the Linux seq command) +[#]: via: (https://www.networkworld.com/article/3511954/generating-numeric-sequences-with-the-linux-seq-command.html) +[#]: author: (Sandra Henry-Stocker https://www.networkworld.com/author/Sandra-Henry_Stocker/) + +使用 Linux seq 命令生成数字序列 +====== +Linux seq 命令可以以闪电般的速度生成数字列表。它易于使用而且灵活。 +[Jamie][1] [(CC BY 2.0)][2] + +在 Linux 中生成数字列表的最简单方法之一是使用 **seq**（sequence）命令。最简单的形式是，**seq** 接收一个数字，并输出从 1 到该数字的列表。例如： + +``` +$ seq 5 +1 +2 +3 +4 +5 +``` + +除非另有指定，否则 **seq** 始终以 1 开头。你可以在最终数字前面插上不同数字开始。 + +``` +$ seq 3 5 +3 +4 +5 +``` + +### 指定增量 + +你还可以指定增量。假设你要列出 3 的倍数。指定起点（在此示例中为第一个 3 ），增量（第二个 3）和终点（18）。 + +``` +$ seq 3 3 18 +3 +6 +9 +12 +15 +18 +``` + +你可以选择使用负增量（即减量）将数字从大变小。 + +``` +$ seq 18 -3 3 +18 +15 +12 +9 +6 +3 +``` + +**seq** 命令也非常快。你或许可以在 10 秒内生成一百万个数字的列表。 + +Advertisement + +``` +$ time seq 1000000 +1 +2 +3 +… +… +999998 +999999 +1000000 + +real 0m9.290s <== 9+ seconds +user 0m0.020s +sys 0m0.899s +``` + +## 使用分隔符 + +另一个非常有用的选项是使用分隔符。你可以插入逗号，冒号或其他一些字符，而不是在每行上列出单个数字。-s 选项后跟要使用的字符。 + +``` +$ seq -s: 3 3 18 +3:6:9:12:15:18 +``` + +实际上，如果只是希望将数字列在一行上，那么可以使用空格代替默认的换行符。 + +``` +$ seq -s' ' 3 3 18 +3 6 9 12 15 18 +``` + +### 开始数学运算 + +从生成数字序列到进行数学运算似乎是一个巨大的飞跃，但是有了正确的分隔符，**seq** 可以轻松地传递给 **bc** 进行计算。例如： + +``` +$ seq -s* 5 | bc +120 +``` + +该命令中发生了什么？让我们来看看。首先，**seq** 生成一个数字列表，并使用 \* 作为分隔符。 + +``` +$ seq -s* 5 +1*2*3*4*5 +``` + +然后，它将字符串传递给计算器 （**bc**），计算器立即将数字相乘。你可以在不到一秒的时间内进行相当广泛的计算。 + +``` +$ time seq -s* 117 | bc +39699371608087208954019596294986306477904063601683223011297484643104\ +22041758630649341780708631240196854767624444057168110272995649603642\ +560353748940315749184568295424000000000000000000000000000 + +real 0m0.003s +user 0m0.004s +sys 0m0.000s +``` + +### 局限性 + +你只能选择一个分隔符，因此计算将非常有限。单独使用 **bc** 可进行更复杂的数学运算。此外，**seq** 仅适用于数字。要生成单个字母序列，请改用如下命令： + +``` +$ echo {a..g} +a b c d e f g +``` + +加入 [Facebook][5] 和 [LinkedIn][6] 上的 Network World 社区，评论热门主题。 + +-------------------------------------------------------------------------------- + +via: https://www.networkworld.com/article/3511954/generating-numeric-sequences-with-the-linux-seq-command.html + +作者：[Sandra Henry-Stocker][a] +选题：[lujun9972][b] +译者：[geekpi](https://github.com/geekpi) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.networkworld.com/author/Sandra-Henry_Stocker/ +[b]: https://github.com/lujun9972 +[1]: https://creativecommons.org/licenses/by/2.0/ +[2]: https://creativecommons.org/licenses/by/2.0/legalcode +[5]: https://www.facebook.com/NetworkWorld/ +[6]: https://www.linkedin.com/company/network-world