| Win32Exts | = | %w{.exe .com .bat} |
| LINKING_SUPPORTED | = | [true] |
| Win32Exts | = | %w{.exe .com .bat} |
In block form, yields the first number of ((lines)) of file ((filename)). In non-block form, it returns an array of the first number of ((lines)).
# Returns first 10 lines of 'myfile'
FileUtils.head("myfile")
[ show source ]
# File lib/facets/core/fileutils/slice.rb, line 14 def head(filename,lines=10) #:yield: a = [] IO.foreach(filename){|line| break if lines <= 0 lines -= 1 if block_given? yield line else a << line end } return a.empty? ? nil : a end
Attempt to do a normal file link, but fall back to a copy if the link fails.
[ show source ]
# File lib/facets/core/fileutils/safe_ln.rb, line 15 def safe_ln(*args) unless LINKING_SUPPORTED[0] cp(*args) else begin ln(*args) rescue Errno::EOPNOTSUPP LINKING_SUPPORTED[0] = false cp(*args) end end end
In block form, yields lines ((from))-((to)). In non-block form, returns an array of lines ((from))-((to)).
# Returns lines 8-12 of 'myfile'
FileUtils.body("myfile",8,12)
[ show source ]
# File lib/facets/core/fileutils/slice.rb, line 52 def slice(filename,from,to) #:yield: IO.readlines(filename)[from-1..to-1] end
Splits a file path into an array of individual path components. This differs from File.split, which divides the path into only two parts, directory path and basename.
split_all("a/b/c") => ['a', 'b', 'c']
[ show source ]
# File lib/facets/core/fileutils/split_all.rb, line 12 def split_all(path) head, tail = File.split(path) return [tail] if head == '.' || tail == '/' return [head, tail] if head == '/' return split_all(head) + [tail] end
In block form, yields the last number of ((lines)) of file ((filename)). In non-block form, it returns the lines as an array.
Note that this method slurps the entire file, so I don’t recommend it for very large files. If you want an advanced form of ((tail)), I suggest using file-tail, by Florian Frank (available on the RAA). And no tail -f.
# Returns last 3 lines of 'myfile'
FileUtils.tail("myfile",3)
[ show source ]
# File lib/facets/core/fileutils/slice.rb, line 39 def tail(filename,lines=10) #:yield IO.readlines(filename).reverse[0..lines-1].reverse end
With no arguments, returns a four element array consisting of the number of bytes, characters, words and lines in filename, respectively.
Valid options are bytes, characters (or just ‘chars’), words and lines.
# Return the number of words in 'myfile'
FileUtils.wc("myfile",'words')
[ show source ]
# File lib/facets/core/fileutils/wc.rb, line 19 def wc(filename,option='all') option.downcase! valid = %w/all bytes characters chars lines words/ unless valid.include?(option) raise "Invalid option: '#{option}'" end n = 0 if option == 'lines' IO.foreach(filename){ n += 1 } return n elsif option == 'bytes' File.open(filename){ |f| f.each_byte{ n += 1 } } return n elsif option == 'characters' || option == 'chars' File.open(filename){ |f| while f.getc n += 1 end } return n elsif option == 'words' IO.foreach(filename){ |line| n += line.split.length } return n else bytes,chars,lines,words = 0,0,0,0 IO.foreach(filename){ |line| lines += 1 words += line.split.length chars += line.split('').length } File.open(filename){ |f| while f.getc bytes += 1 end } return [bytes,chars,words,lines] end end
In block form, yields each ((program)) within ((path)). In non-block form, returns an array of each ((program)) within ((path)). Returns (({nil})) if not found.
On the MS Windows platform, it looks for executables ending with .exe, .bat and .com, which you may optionally include in the program name.
File.whereis("ruby") -> ['/usr/local/bin/ruby','/opt/bin/ruby']
[ show source ]
# File lib/facets/core/fileutils/whereis.rb, line 25 def whereis(prog, path=ENV['PATH']) #:yield: dirs = [] path.split(File::PATH_SEPARATOR).each{|dir| # Windows checks against specific extensions if File::ALT_SEPARATOR if prog.include?('.') f = File.join(dir,prog) if File.executable?(f) && !File.directory?(f) if block_given? yield f.gsub(/\//,'\\') else dirs << f.gsub(/\//,'\\') end end else Win32Exts.find_all{|ext| f = File.join(dir,prog+ext) if File.executable?(f) && !File.directory?(f) if block_given? yield f.gsub(/\//,'\\') else dirs << f.gsub(/\//,'\\') end end } end else f = File.join(dir,prog) # Avoid /usr/lib/ruby, for example if File.executable?(f) && !File.directory?(f) if block_given? yield f else dirs << f end end end } dirs.empty? ? nil : dirs end
Looks for the first occurrence of program within path.
On the MS Windows platform, it looks for executables ending with .exe, .bat and .com, which you may optionally include in the program name. Returns nil if not found.
[ show source ]
# File lib/facets/core/fileutils/which.rb, line 28 def which(prog, path=ENV['PATH']) path.split(File::PATH_SEPARATOR).each {|dir| # Windows checks against specific extensions if File::ALT_SEPARATOR ext = Win32Exts.find{|ext| if prog.include?('.') # Assume extension already included f = File.join(dir,prog) else f = File.join(dir,prog+ext) end File.executable?(f) && !File.directory?(f) } if ext # Use backslashes, not forward slashes if prog.include?('.') # Assume extension already included f = File.join( dir, prog ).gsub(/\//,'\\') else f = File.join( dir, prog + ext ).gsub(/\//,'\\') end return f end else f = File.join(dir,prog) # Avoid /usr/lib/ruby, for example if File.executable?(f) && !File.directory?(f) return File::join( dir, prog ) end end } nil end