bash Shell 脚本输出格式
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Shell Script output formatting
提问by Vijay
I have output from a shell script like below
我有一个 shell 脚本的输出，如下所示
output1 ..... 1
output2 ..... 2
output3 ............3
I tried to format it with equal spacing inside script but output still not have uniform spacing.
我试图在脚本内以相等的间距格式化它，但输出仍然没有统一的间距。
I want to print the output like below.
我想打印如下输出。
output1 ..... 1
output2 ..... 2
output3 ......3
Are there any commnads available to get this done. I use bash.
是否有任何可用的命令来完成此操作。我使用 bash。
here is the code.
这是代码。
lnode=abc
printf "server name ......... "$lnode""
printf "\nserver uptime and load details : ......... `uptime`"
printf "\n"
lcpu=`cat /proc/cpuinfo | grep -i process |wc -l`
printf "Total number of CPUs on this server : ......... $lcpu\n"
-Thanks.
-谢谢。
回答by John1024
The idea of printfis that you specify a format string that specifies column widths, etc:
想法printf是您指定一个指定列宽等的格式字符串：
$ cat script.sh
lnode=abc
printf "%-40s %s\n" "server name :" "......... $lnode"
printf "%-40s %s\n" "server uptime and load details :" "......... `uptime`"
lcpu=$(cat /proc/cpuinfo | grep -i process |wc -l)
printf "%-40s %s\n" "Total number of CPUs on this server :" "......... $lcpu"
The first directive in the format string, %-40s, is applied to the first argument that follows the format string. It tells printf to display that argument in a 40-character-wide column. If we had used %40s, it would be a right-aligned column. I specified %-40sso that it would be left-aligned.
格式字符串中的第一个指令应用于格式字符串%-40s后面的第一个参数。它告诉 printf 在 40 个字符宽的列中显示该参数。如果我们使用了%40s，它将是一个右对齐的列。我指定%-40s它是左对齐的。
This produces output like:
这会产生如下输出：
$ bash script.sh
server name : ......... abc
server uptime and load details : ......... 18:05:50 up 17 days, 20 users, load average: 0.05, 0.20, 0.33
Total number of CPUs on this server : ......... 4
Documentation
文档
Bash's printfcommand is similar to printfin other languages, particularly the C version. Details specific to bash are found in man bash. Detailed information about the available format options is found in man 3 printf. To begin, however, you are probably better served by a tutorial such as this oneor this oneor this one.
Bash 的printf命令类似于printf其他语言，尤其是 C 版本。特定于 bash 的详细信息可以在man bash. 有关可用格式选项的详细信息可在 中找到man 3 printf。但是，一开始，您可能更适合阅读诸如this one或this one或this one 之类的教程。
