红宝石扫描法

Question

嗨，我正试图用扫描方法解析这个字符串

test = "Disk/File System/[/dev/mapper/rhel-var (/var)]/MB free=14791, Disk/File System/[/dev/mapper/rhel-home (/home)]/MB free=9451, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/percent full=1.0"

我必须捕获路径：/dev/mapper/rhel-var (/var)和百分比上的数字：1.0

我试过很多次，但我可以让它开始工作。

testa = test.gsub(',', '')
r = testa.scan(/Disk\/File System\/\[((.*))\]\/percent full=([^[:space:]]+)/)
puts r

--编辑--

字符串可以具有FS的多个ocurrence和百分比：

test = "Disk/File System/[/dev/mapper/rhel-var (/var)]/MB free=14791, Disk/File System/[/dev/mapper/rhel-home (/home)]/MB free=9451, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/percent full=1.0, Disk/File System/[/dev/sda2 (/boot)]/MB total=1974, Disk/File System/[/dev/mapper/rhel-home (/home)]/MB total=10015, Disk/File System/[/dev/mapper/rhel-root (/)]/percent full=61.0, Disk/File System/[/dev/mapper/rhel-var (/var)]/percent full=23.0, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB total=452543, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB free=426145, Disk/File System/[/dev/mapper/rhel-root (/)]/MB total=10015, Disk/File System/[/dev/mapper/rhel-root (/)]/MB free=3717, Disk/File System/[/dev/mapper/rhel-var (/var)]/MB total=20030, Disk/File System/[/dev/sda2 (/boot)]/percent full=9.0, Disk/File System/[/dev/sda2 (/boot)]/MB free=1699, Disk/File System/[/dev/mapper/rhel-home (/home)]/percent full=1.0, Disk/File System/[devtmpfs (/dev)]/MB total=3851, Disk/File System/[devtmpfs (/dev)]/percent full=0.0, Disk/File System/[devtmpfs (/dev)]/MB free=3851"

帮帮忙，谢谢

Answer 1

您可以使用

/Disk\/File System\/\[([^\]\[]*)\]\/percent full=(\d+(?:\.\d+)?)/

见Rubular演示 (regex101演示)。详细信息

• Disk\/File System\/\[ -一个Disk/File System/[字符串
• ([^\]\[]*) -第1组:除[和]以外的任何零或多个字符，尽可能多
• \]\/percent full= -一个]/percent full=文本
• (\d+(?:\.\d+)?) -第2组:一个或多个数字，然后是一个可选的.序列和一个或多个数字。

在Ruby中

test = "Disk/File System/[/dev/mapper/rhel-var (/var)]/MB free=14791, Disk/File System/[/dev/mapper/rhel-home (/home)]/MB free=9451, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/percent full=1.0, Disk/File System/[/dev/sda2 (/boot)]/MB total=1974, Disk/File System/[/dev/mapper/rhel-home (/home)]/MB total=10015, Disk/File System/[/dev/mapper/rhel-root (/)]/percent full=61.0, Disk/File System/[/dev/mapper/rhel-var (/var)]/percent full=23.0, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB total=452543, Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB free=426145, Disk/File System/[/dev/mapper/rhel-root (/)]/MB total=10015, Disk/File System/[/dev/mapper/rhel-root (/)]/MB free=3717, Disk/File System/[/dev/mapper/rhel-var (/var)]/MB total=20030, Disk/File System/[/dev/sda2 (/boot)]/percent full=9.0, Disk/File System/[/dev/sda2 (/boot)]/MB free=1699, Disk/File System/[/dev/mapper/rhel-home (/home)]/percent full=1.0, Disk/File System/[devtmpfs (/dev)]/MB total=3851, Disk/File System/[devtmpfs (/dev)]/percent full=0.0, Disk/File System/[devtmpfs (/dev)]/MB free=3851"
rx = /Disk\/File System\/\[([^\]\[]*)\]\/percent full=(\d+(?:\.\d+)?)/
puts test.scan(rx)

输出：

[
   ["/dev/mapper/rhel-opt (/opt)", "1.0"],
   ["/dev/mapper/rhel-root (/)", "61.0"],
   ["/dev/mapper/rhel-var (/var)", "23.0"],
   ["/dev/sda2 (/boot)", "9.0"],
   ["/dev/mapper/rhel-home (/home)", "1.0"],
   ["devtmpfs (/dev)", "0.0"]
]

Answer 2

我将按如下方式编写字符串，以澄清其结构。

test = "Disk/File System/[/dev/mapper/rhel-var (/var)]/MB free=14791," +
       "Disk/File System/[/dev/mapper/rhel-home (/home)]/MB free=9451," +
       "Disk/File System/[/dev/mapper/rhel-opt (/opt)]/percent full=1.0," +
       "Disk/File System/[/dev/sda2 (/boot)]/MB total=1974," +
       "Disk/File System/[/dev/mapper/rhel-home (/home)]/MB total=10015, " +
       "Disk/File System/[/dev/mapper/rhel-root (/)]/percent full=61.0," +
       "Disk/File System/[/dev/mapper/rhel-var (/var)]/percent full=23.0, " +
       "Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB total=452543, " +
       "Disk/File System/[/dev/mapper/rhel-opt (/opt)]/MB free=426145," +
       "Disk/File System/[/dev/mapper/rhel-root (/)]/MB total=10015," +     
       "Disk/File System/[/dev/mapper/rhel-root (/)]/MB free=3717," +
       "Disk/File System/[/dev/mapper/rhel-var (/var)]/MB total=20030," +
       "Disk/File System/[/dev/sda2 (/boot)]/percent full=9.0," +
       "Disk/File System/[/dev/sda2 (/boot)]/MB free=1699," +
       "Disk/File System/[/dev/mapper/rhel-home (/home)]/percent full=1.0, " +
       "Disk/File System/[devtmpfs (/dev)]/MB total=3851, " +
       "Disk/File System/[devtmpfs (/dev)]/percent full=0.0, " +
       "Disk/File System/[devtmpfs (/dev)]/MB free=3851"

我假设您希望提取所有对路径和“百分比满”值，而不考虑后面没有“百分比满”的路径。

你可以写

r = /\bDisk\/File System\/\[([^\]]+)\]\/percent full=(\d+\.\d)/

test.scan(r)
  #=> [["/dev/mapper/rhel-opt (/opt)", "1.0"],
  #    ["/dev/mapper/rhel-root (/)", "61.0"],
  #    ["/dev/mapper/rhel-var (/var)", "23.0"],
  #    ["/dev/sda2 (/boot)", "9.0"],
  #    ["/dev/mapper/rhel-home (/home)", "1.0"],
  #    ["devtmpfs (/dev)", "0.0"]]

正则表达式可以以自由间隔模式编写，以使其自文档化。

r = /
    \b                     # assert a word break
    Disk\/File System\/\[  # match a string
    ([^\]]+)               # match 1 or more chars other than ']',
                           #   saved to capture group 1
    \]\/percent[ ]full=    # match a string
    (\d+\.\d)              # match one or more digits followed by '.', followed
                           #   by one digit, saved to capture group 2 
    /x                     # invoke free-spacing regex definition mode

请注意，在自由间距模式下，如果表达式没有以某种方式受到保护，则在解析表达式之前，percent和full之间的空间将被删除。就像我所做的那样，将字符类中的空间围起来是几种方法之一。