File editing

Table of contents

Prerequisites

Read the tutorial Tutorial for running examples
Ensure you have read and understand the section on how to make an example stand alone
Ensure you have read the note at the end of that section regarding modification of the body common control to the following:

 code
body common control
{
  inputs => {
    "libraries/cfengine_stdlib.cf",
  };
}

Note: This change is not necessary for supporting each of the examples in this tutorial. It will be included only in those examples that require it.

List files

Note: The following workflow assumes the directory /home/user already exists. If it does not either create the directory or adjust the example to a path of your choosing.

Create a file /var/cfengine/masterfiles/file_test.cf that includes the following text:

 file_test.cf
bundle agent list_file
{
 vars:
   "ls"
     slist => lsdir("/home/user", "test_plain.txt", "true");
 reports:
    "ls: $(ls)";
}

Run the following command to remove any existing test file at the location we wish to use for testing this example:
command
```
rm /home/user/test_plain.txt
```
Test to ensure there is no file /home/user/test_plain.txt, using the following command (the expected result is that there should be no file listed at the location /home/user/test_plain.txt):
command
```
ls /home/user/test_plain.txt
```
Run the following command to instruct CFEngine to see if the file exists (the expected result is that no report will be generated (because the file does not exist):
command
```
/var/cfengine/bin/cf-agent --no-lock --file /var/cfengine/masterfiles/file_test.cf --bundlesequence list_file
```
Create a file for testing the example, using the following command:
command
```
touch /home/user/test_plain.txt
```
Run the following command to instruct CFEngine to search for the file (the expected result is that a report will be generated, because the file exists):
command
```
/var/cfengine/bin/cf-agent --no-lock --file /var/cfengine/masterfiles/file_test.cf --bundlesequence list_file
```
Double check the file exists, using the following command (the expected result is that there will be a file listed at the location /home/user/test_plain.txt):
command
```
ls /home/user/test_plain.txt
```
Run the following command to remove the file:
command
```
rm /home/user/test_plain.txt
```

Create a file

 file_create.cf
bundle agent testbundle
{
  files:
    "/home/user/test_plain.txt"
      perms => system,
      create => "true";
}

bundle agent list_file
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");
  reports:
    "ls: $(ls)";
}

bundle agent list_file_2
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");  reports:
      "ls: $(ls)";
}

body perms system
{
  mode => "0640";
}

 code
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt

Delete a file

 file_delete.cf
body common control
{
  inputs => {
    "libraries/cfengine_stdlib.cf",
  };
}

bundle agent testbundle
{
  files:
    "/home/user/test_plain.txt"
      perms => system,
      create => "true";
}

bundle agent test_delete
{
  files:
    "/home/user/test_plain.txt"
      delete => tidy;
}

bundle agent list_file
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");
  reports:
    "ls: $(ls)";
}

bundle agent list_file_2
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");
  reports:
    "ls: $(ls)";
}

body perms system
{
  mode  => "0640";
}

 code
rm /home/user/test_plain.txt
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,test_delete,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt

(last command will throw an error because the file doesn't exist!)

Modify a File

 code
rm /home/user/test_plain.txt
ls /home/user/test_plain.txt
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,testbundle,list_file_2
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,list_file_2

 file_modify.cf
body common control
{
  inputs => {
    "libraries/cfengine_stdlib.cf",
  };
}

bundle agent testbundle
{
  files:
    "/home/user/test_plain.txt"
      perms => system,
      create => "true";
}

bundle agent test_delete
{
  files:
    "/home/user/test_plain.txt"
      delete => tidy;
}

bundle agent list_file
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");
  reports:
    "ls: $(ls)";
}

bundle agent list_file_2
{
  vars:
    "ls"
      slist => lsdir("/home/user", "test_plain.txt", "true");
  reports:
    "ls: $(ls)";
}

# Finds the file, if exists calls bundle to edit line
bundle agent outer_bundle_1
{
  files:
    "/home/user/test_plain.txt"
      create => "false",
      edit_line => inner_bundle_1;
}

# Finds the file, if exists calls bundle to edit line
bundle agent outer_bundle_2
{
  files:
    "/home/user/test_plain.txt"
      create => "false",
      edit_line => inner_bundle_2;
}

# Inserts lines
bundle edit_line inner_bundle_1
{
  vars:
    "msg"
      string => "Helloz to World!";
  insert_lines:
    "$(msg)";
}

# Replaces lines
bundle edit_line inner_bundle_2
{
  replace_patterns:
    "Helloz to World!"
      replace_with => hello_world;
}

body replace_with hello_world
{
  replace_value => "Hello World";
  occurrences => "all";
}

body perms system
{
  mode  => "0640";
}

 code
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence list_file,test_delete,list_file_2
ls /home/user/test_plain.txt
rm /home/user/test_plain.txt

Copy a file and edit its text

 file_copy.cf
body common control
{
  inputs => {
    "libraries/cfengine_stdlib.cf",
  };
}

bundle agent testbundle
{
  files:
    "/home/ichien/test_plain.txt"
      perms => system,
      create => "true";
  reports:
    "test_plain.txt has been created";
}

bundle agent test_delete
{
  files:
    "/home/ichien/test_plain.txt"
      delete => tidy;
}

bundle agent do_files_exist
{
  vars:
    "mylist"
      slist => {
        "/home/ichien/test_plain.txt",
        "/home/ichien/test_plain_2.txt",
      };
  classes:
    "exists"
      expression => filesexist("@(mylist)");
  reports:
    exists::
      "test_plain.txt and test_plain_2.txt files exist";
    !exists::
      "test_plain.txt and test_plain_2.txt files do not exist";
}

bundle agent do_files_exist_2
{
  vars:
    "mylist"
      slist => {
        "/home/ichien/test_plain.txt",
        "/home/ichien/test_plain_2.txt"
      };
  classes:
    "exists"
      expression => filesexist("@(mylist)");
  reports:
    exists::
      "test_plain.txt and test_plain_2.txt files both exist";
    !exists::
      "test_plain.txt and test_plain_2.txt files do not exist";
}

bundle agent list_file_1
{
  vars:
    "ls1"
      slist => lsdir("/home/ichien", "test_plain.txt", "true");
    "ls2"
      slist => lsdir("/home/ichien", "test_plain_2.txt", "true");
    "file_content_1"
      string => readfile("/home/ichien/test_plain.txt", "33");
    "file_content_2"
      string => readfile("/home/ichien/test_plain_2.txt", "33");
  reports:
    # "ls1: $(ls1)";
    # "ls2: $(ls2)";
    "Contents of /home/ichien/test_plain.txt = $(file_content_1)";
    "Contents of /home/ichien/test_plain_2.txt = $(file_content_2)";
}

bundle agent list_file_2
{
  vars:
    "ls1"
      slist => lsdir("/home/ichien", "test_plain.txt", "true");
    "ls2"
      slist => lsdir("/home/ichien", "test_plain_2.txt", "true");
    "file_content_1"
      string => readfile("/home/ichien/test_plain.txt", "33");
    "file_content_2"
      string => readfile("/home/ichien/test_plain_2.txt", "33");
  reports:
    # "ls1: $(ls1)";
    # "ls2: $(ls2)";
    "Contents of /home/ichien/test_plain.txt = $(file_content_1)";
    "Contents of /home/ichien/test_plain_2.txt = $(file_content_2)";
}

bundle agent outer_bundle_1
{
  files:
    "/home/ichien/test_plain.txt"
      create => "false",
      edit_line => inner_bundle_1;
}

# Copies file
bundle agent copy_a_file
{
  files:
    "/home/ichien/test_plain_2.txt"
      copy_from => local_cp("/home/ichien/test_plain.txt");
  reports:
    "test_plain.txt has been copied to test_plain_2.txt";
}

bundle agent outer_bundle_2
{
  files:
    "/home/ichien/test_plain_2.txt"
      create => "false",
      edit_line => inner_bundle_2;
}

bundle edit_line inner_bundle_1
{
  vars:
    "msg"
      string => "Helloz to World!";
  insert_lines:
    "$(msg)";
  reports:
    "inserted $(msg) into test_plain.txt";
}

bundle edit_line inner_bundle_2
{
  replace_patterns:
    "Helloz to World!"
      replace_with => hello_world;
  reports:
    "Text in test_plain_2.txt has been replaced";
}

body replace_with hello_world
{
  replace_value => "Hello World";
  occurrences => "all";
}

body perms system
{
  mode  => "0640";
}

 command
/var/cfengine/bin/cf-agent --no-lock --file ./file_test.cf --bundlesequence test_delete,do_files_exist,testbundle,outer_bundle_1,copy_a_file,do_files_exist_2,list_file_1,outer_bundle_2,list_file_2