Class: File

Inherits:
Object
  • Object
show all
Defined in:
lib/fileutil.rb

Instance Method Summary collapse

Instance Method Details

#ff(*args) ⇒ Object

fast forward until it finds one of args supplied as string or regex returns nil if nothing found



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# File 'lib/fileutil.rb', line 86

def ff *args
  p = pos
  re = Regexp.union(args)
  @find_registry = { :method => :ff, :re => re }
  buffer = 512
  begin
    psearch = pos
    chunk = read(buffer) || ''
    seek(-80,1) unless eof?
    check = chunk.index(re)
  end while check.nil? and !eof?
  begin
    seek(psearch + check)
    return self
  rescue
    seek p
    return nil
  end
end

#ff?(*args) ⇒ Boolean

do not fast forward, just give the position that ff would fast forward to.

Returns:

  • (Boolean) 


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# File 'lib/fileutil.rb', line 42

def ff? *args
  p = pos 
  p1 = ff(*args)
  p1.nil? ? p1 = nil : p1 = pos
  seek p
  return p1
end

#findall(*args) ⇒ Object

find all occurences of args (with or) in the file egardless of the current position



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# File 'lib/fileutil.rb', line 19

def findall *args
  p = pos
  seek(0)
  results = [ ff(*args).pos ]
  while !repeat.nil?
    results.push pos
  end
  seek(p)
  return results
end

#head(n, cur = false, reset = true) ⇒ Object

unix head like utility, returns lines as an array. optional arguments cur for start from current line (default is start) from beggining; reset for do not change current position (default). head leaves cursor at the beginning of the first line it doesn’t return if reset false



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# File 'lib/fileutil.rb', line 112

def head(n, cur=false, reset=true)
  #eof guard
  p = pos
  line_start
  lines = []
  seek(0) unless cur
  for i in 1..n 
    break if eof?
    lines.push(readline.chomp)
  end
  seek(p) if reset
  return lines unless lines.length == 0
  return nil
end

#line_end ⇒ Object

move to the last char of current line



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# File 'lib/fileutil.rb', line 167

def line_end
  return ff(/$/)
end

#line_start ⇒ Object

move to the first char of current line



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# File 'lib/fileutil.rb', line 157

def line_start
  if pos > 0
    seek(-1,1) 
    return self if readchar == "\n" 
  elsif pos == 0
    return self
  end
  return rew(/^/) 
end

#repeat ⇒ Object

repeat last ff/rew command



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# File 'lib/fileutil.rb', line 3

def repeat
  if @find_registry[:method] == :ff
    seek(1,1)
    if ff(@find_registry[:re]).nil?
      seek(-1,1) 
      return nil
    else
      return self
    end
  else
    rew(@find_registry[:re])
  end
end

#rew(*args) ⇒ Object

rewind until it finds one of args supplied as string or regex returns nil if nothing found



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# File 'lib/fileutil.rb', line 52

def rew *args
  p = pos
  psearch = p
  re = Regexp.union(args)
  @find_registry = { :method => :rew, :re => re }
  begin
    break if psearch == 0
    512 > pos ? buffer = pos : buffer = 512 # buffer = [512, p].min
    seek(-buffer, 1)
    psearch = pos
    chunk = read(buffer+80)
    seek(-chunk.length, 1)
    check = chunk.rindex(re)
    if !check.nil? and buffer <= check
      chunk.slice!(-(chunk.length-buffer)..-1)
      check = chunk.rindex(re)
    end
  end while check.nil? or buffer <= check 
  begin
    if buffer <= check
      seek p
      return nil
    else 
      seek(psearch + check)
      return self
    end
  rescue
    seek p
    return nil
  end
end

#rew?(*args) ⇒ Boolean

do not rewind, just give the position that rew would rewind to.

Returns:

  • (Boolean) 


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# File 'lib/fileutil.rb', line 32

def rew? *args
  p = pos 
  p1 = rew(*args)
  p1.nil? ? p1 = nil : p1 = pos
  seek p
  return p1
end

#tail(n, cur = false, reset = true) ⇒ Object

unix tail like utility, returns lines as an array. optional arguments cur for start from current line (default is start) from end; reset for do not change current position (default). tail leaves ‘cursor’ at the end of last line it doesn’t return if reset false



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# File 'lib/fileutil.rb', line 133

def tail(n, cur=false, reset=true)
  p = pos
  chunks = '$'
  lines = 0
  cur ? line_end.seek(1,1) : seek(size)
  begin
    p1 = pos
    p1 < 512 ? buffer = p1 : buffer = 512
    seek(-buffer, 1)
    chunk = read(buffer)
    lines += chunk.count("\n")
    chunks = chunk + chunks
    seek(-chunk.size,1)
  end while lines < ( n + 1 ) && p1 > buffer
  ary = chunks.split(/\n/)
  ary.pop
  if reset 
    seek(p) 
  else
    seek(p1-2-(ary.last(n).join("\n").length)) rescue seek 0
  end
  return ary.last(n).reverse
end