shell tools: globbing

2019-05-10 08:08:49 -04:00
parent 8ea2598254
commit 86cba3b585
35 changed files with 303 additions and 432 deletions
--- a/shellex/apis/globtopattern.lua
+++ b/shellex/apis/globtopattern.lua
@@ -0,0 +1,119 @@
+-- see: https://github.com/davidm/lua-glob-pattern
+local M = {_TYPE='module', _NAME='globtopattern', _VERSION='0.2.1.20120406'}
+
+function M.globtopattern(g)
+  -- Some useful references:
+  -- - apr_fnmatch in Apache APR.  For example,
+  --   http://apr.apache.org/docs/apr/1.3/group__apr__fnmatch.html
+  --   which cites POSIX 1003.2-1992, section B.6.
+
+  local p = "^"  -- pattern being built
+  local i = 0    -- index in g
+  local c        -- char at index i in g.
+
+  -- unescape glob char
+  local function unescape()
+    if c == '\\' then
+      i = i + 1; c = g:sub(i,i)
+      if c == '' then
+        p = '[^]'
+        return false
+      end
+    end
+    return true
+  end
+
+  -- escape pattern char
+  local function escape(c)
+    return c:match("^%w$") and c or '%' .. c
+  end
+
+  -- Convert tokens at end of charset.
+  local function charset_end()
+    while 1 do
+      if c == '' then
+        p = '[^]'
+        return false
+      elseif c == ']' then
+        p = p .. ']'
+        break
+      else
+        if not unescape() then break end
+        local c1 = c
+        i = i + 1; c = g:sub(i,i)
+        if c == '' then
+          p = '[^]'
+          return false
+        elseif c == '-' then
+          i = i + 1; c = g:sub(i,i)
+          if c == '' then
+            p = '[^]'
+            return false
+          elseif c == ']' then
+            p = p .. escape(c1) .. '%-]'
+            break
+          else
+            if not unescape() then break end
+            p = p .. escape(c1) .. '-' .. escape(c)
+          end
+        elseif c == ']' then
+          p = p .. escape(c1) .. ']'
+          break
+        else
+          p = p .. escape(c1)
+          i = i - 1 -- put back
+        end
+      end
+      i = i + 1; c = g:sub(i,i)
+    end
+    return true
+  end
+
+  -- Convert tokens in charset.
+  local function charset()
+    i = i + 1; c = g:sub(i,i)
+    if c == '' or c == ']' then
+      p = '[^]'
+      return false
+    elseif c == '^' or c == '!' then
+      i = i + 1; c = g:sub(i,i)
+      if c == ']' then
+        -- ignored
+      else
+        p = p .. '[^'
+        if not charset_end() then return false end
+      end
+    else
+      p = p .. '['
+      if not charset_end() then return false end
+    end
+    return true
+  end
+
+  -- Convert tokens.
+  while 1 do
+    i = i + 1; c = g:sub(i,i)
+    if c == '' then
+      p = p .. '$'
+      break
+    elseif c == '?' then
+      p = p .. '.'
+    elseif c == '*' then
+      p = p .. '.*'
+    elseif c == '[' then
+      if not charset() then break end
+    elseif c == '\\' then
+      i = i + 1; c = g:sub(i,i)
+      if c == '' then
+        p = p .. '\\$'
+        break
+      end
+      p = p .. escape(c)
+    else
+      p = p .. escape(c)
+    end
+  end
+  return p
+end
+
+return M