One-step learning of Ruby (21): File Operations 2

1. Open and read files

 
File = file. Open ("cnblogslink.txt") file. Each {| Line | print "# {file. lineno}.", line} file. Close
 

Output:

1.Community

2. News

3. Community

4. News

5. Recruitment

6. Bo Wen

7. Group
8. Flash
9. Network Abstract
10.. Net Channels

File. lineno displays the row number.

2. argv and argf

Argv

 
Argv <"cnblogslink.txt" # The gets method is a kernel method that gets lines from argvprint while getsp argv. class = begin output: Community news community news recruitment Q & A Team Flash network Abstract. net channel Array = end
 

Argf

Let's write the following in test. RB:Code:

While line = argf. Gets print lineend
 

Run the following command in the command line:

 
C: \ studyruby> test. RB cnblogslink.txt cnblogslink2.txt community news recruitment blog Q & A Team Flash network extraction. Net channel Community news community news recruitment blog Q & A Team Flash network extraction. Net Channel
 

3. File Information Query

# Does the file have P file: exists? ("Cnblogslink.txt") # => true # Is it a file P file. file? ("Cnblogslink.txt") # => true # Is it the directory P file: directory? ("C:/ruby") # => truep file: directory? ("Cnblogslink.txt") #=> false # File Permission P file. readable? ("Cnblogslink.txt") # => truep file. writable? ("Cnblogslink.txt") # => truep file.exe cutable? ("Cnblogslink.txt") # => false # Is it a zero-length P file. Zero? ("Cnblogslink.txt") # => false # file size bytesp file. Size? ("Cnblogslink.txt") # => 74 P file. size ("cnblogslink.txt") # => 74 # file or folder P file: FTYPE ("cnblogslink.txt ") # => "file" # file creation, modification, and last access time P file: ctime ("cnblogslink.txt") # => sat Sep 19 08:05:07 + 0800 2009 P file :: mtime ("cnblogslink.txt") # => sat Sep 19 08:06:34 + 0800 2009 P file: atime ("cnblogslink.txt") # => sat Sep 19 08:05:07 + 0800 2009
 

4. Search for files

Puts "Find all files and folders in the directory" dir ["C:/Ruby/*"]. each {| x | puts x} puts "condition query" dir. foreach ('C:/Ruby ') {| x | puts X if X! = "." & X! = ".. "} Puts" Find a type of file "dir ["*. RB "]. each {| x | puts x} puts "Open query" dir. open ('C:/Ruby ') {| d | D. grep/L /}. each {| x | puts x} puts "---------------------------" dir. open ('C:/Ruby ') {| d | D. each {| x | puts x} puts "Regular Expression query" dir ["C:/Ruby/[RS] *"]. each {| x | puts x} puts "----------------------" dir ["C:/Ruby/[^ s] *"]. each {| x | puts x} puts "----------------------" dir ["C:/Ruby/{Ruby, Li} *"]. each {| x | Pu TS x} puts "------------------------" dir ["C:/Ruby /? B * "]. each {| x | puts x} puts "find the Directory and subdirectory file" require 'Find 'find. find ('. /') {| path | puts path}
 

The output is as follows:

> Ruby test. find all files and folders in the directory c:/Ruby/binc:/Ruby/changelog.txt C:/Ruby/docc:/Ruby/libc:/Ruby/license.txt C: /Ruby/manc:/Ruby/manifestc:/Ruby/miscc:/Ruby/readme.1stc:/Ruby/releasenotes.txt C:/Ruby. ICOC:/Ruby/rubyopt. DELC:/Ruby/rubyw. ICOC:/Ruby/samplesc:/Ruby/scitec:/Ruby/sharec:/Ruby/SRCC:/Ruby/example find a type of file test. rbtest2.rbopen contains regular expression query ---------------------- C:/Ruby/binc:/Ruby/changelog.txt C:/Ruby/docc:/Ruby/libc:/Ruby/license.txt C:/Ruby/manc: /Ruby/manifestc:/Ruby/miscc:/Ruby/readme.1stc:/Ruby/releasenotes.txt C:/Ruby. ICOC:/Ruby/rubyopt. DELC:/Ruby/rubyw. ICOC:/Ruby/uninstall.exe ---------------------- C:/Ruby. ICOC:/Ruby/rubyopt. DELC:/Ruby/rubyw. ICOC:/Ruby/libc:/Ruby/license.txt ------------------------ find the file in the subdirectory of the directory. /. /test2.rb. /test2./Test2/test2.rb. /Test2/test. RB. /test1./test. RB. /output. /films.txt. /cnblogslink2.txt. /cnblogslink.txt. /beans.txt> exit code: 0