Home Backend Development PHP Tutorial Basic operations on PHP files

Basic operations on PHP files

Jul 25, 2016 am 08:42 AM

  1. //Basic file operations
  2. //fopen()
  3. Open a file
  4. //Open a file using an absolute path, select read-only mode, and return the resource $handle
  5. $handle= fopen("D:/lamp/apache2/htdocs/test/file.txt","r");
  6. //Access files in the document root directory and also select read-only mode
  7. $handle=fopen($_SERVER[' DOCUMENT_ROOT']."/test/file.txt","r");
  8. //Open remote files, which can only be opened in read mode using the http protocol
  9. $handle=fopen("http://www.wowsai. com","r");
  10. //Use FTP protocol to open remote files. If the FTP server is writable, it can be opened in write mode
  11. //$handle=fopen("ftp://user:password@example. com/file.txt",'w');
  12. //fclose()
  13. Close the open resource type
  14. //fwrite()
  15. Write content to the file
  16. $fileName="data.txt";
  17. // Declare a file variable
  18. //Open the file in write-only mode, create it if it does not exist, and pass the program when the opening fails
  19. $f_handle=fopen("data.txt","w")or die("Open< b>".$fileName."File failed");
  20. for($i=0;$i<10;$i++){
  21. //Add content to the file through a loop
  22. fwrite ($f_handle,"againn");
  23. }
  24. fclose($f_handle);
  25. //Close the open file
  26. //file_put_contents()
  27. Write all data to the specified file at once
  28. //Read the file content
  29. //fread()
  30. Read an open file
  31. //file_get_contents()
  32. Read a file into a string
  33. //fgets()
  34. Return a line from an open file
  35. //fgetc()
  36. From an open file Return characters in
  37. //file()
  38. Read the file into an array
  39. //readfile()
  40. Read a file and output it to the output buffer
  41. //feof()
  42. Judge whether a file pointer is at the end of the file At
  43. //Read the specified number of bytes from the file and store it in a variable
  44. $fileName2="data.txt";
  45. $f_hand=fopen($fileName2,"r")or die("Open the file Failed");
  46. $contents=fread($f_hand,50);
  47. fclose($f_hand);
  48. echo $contents."
    ";
  49. //Read all the contents from the file and store them in a variable , read part of it each time, read in a loop
  50. /* $fileName3="D:/lamp/apache2/icons/link.gif";
  51. //Save the file name of the binary file into a variable
  52. $f3_handle= fopen($fileName3,"rb")or die("File opening failed"); //Open the file in read-only mode, the mode is added with "b"
  53. $f3_contents="";
  54. //Declare one for saving String of file content
  55. while(!feof($f3_handle)){
  56. //Loop to read the contents of the file until the end of the file
  57. $f3_contents.=fread($f3_handle,1024);
  58. //Read each time 1024 characters
  59. }
  60. fclose($f3_handle);
  61. echo $f3_contents; */
  62. //Another way to read the entire contents of the file
  63. $fileName4="data.txt";
  64. $f4_handle=fopen($fileName4 ,"r")or die("File opening failed");
  65. $f4_con=fread($f4_handle,filesize($fileName4));
  66. //Use filesize to get the length of the file, so as to read the entire content of the file
  67. fclose($f4_handle);
  68. echo $f4_con."
    ";
  69. //Another method to read the entire contents of the file, which has much better performance than the above
  70. echo file_get_contents("data.txt");
  71. $f5_handle=fopen("data.txt","r") or die("File opening failed");
  72. while(!feof($f5_handle)){
  73. //Determine whether the pointer reaches the end of the file
  74. $buffer= fgets($f5_handle);
  75. //Read one line from the file at a time
  76. echo $buffer."
    ";
  77. }
  78. fclose($f5_handle);
  79. $f6_handle=fopen("data.txt", "r") or die("File opening failed");
  80. while(!feof($f6_handle)){
  81. //Judge whether the pointer reaches the end of the file
  82. $buffer=fgetc($f6_handle);
  83. //Every time from Read a character from the file
  84. echo $buffer."
    ";
  85. }
  86. fclose($f6_handle);
  87. print_r(file("data.txt"));
  88. //Read the file into an array
  89. readfile("data.txt");
  90. //Read the contents of the file directly and output it to the browser
  91. //Access remote files
  92. Make sure "allow_url_fopen" in php.ini is turned on, and make sure The remote file has access permission
  93. $ws_file=fopen("http://www.wowsai.com","r")or die("Remote file opening failed");
  94. //Open the remote file
  95. while(!feof( $ws_file)){
  96. $ws_line=fgets($ws_file);
  97. if(preg_match("/(.*)/",$ws_line,$res)){
  98. //Use Regularly matches the title of the website
  99. $title=$res[1];
  100. break;
  101. }
  102. }
  103. fclose($ws_file);
  104. echo $title."
    ";
  105. //Move the pointer of the file
  106. //ftell()
  107. Return the current position of the pointer
  108. //fseek()
  109. Move the pointer to the specified Position
  110. //rewind()
  111. Move the pointer to the beginning of the file
  112. $fp=fopen("data.txt","r") or die("File opening failed");
  113. //Open the file in read-only mode
  114. echo ftell($fp)."
    ";
  115. //Output the position of the pointer when the file was just opened. The default is 0
  116. echo fread($fp,10)."
    ";
  117. // After reading the first 10 characters of the file, the file pointer has changed
  118. echo ftell($fp)."
    ";
  119. //After reading the first 10 characters of the file, the file pointer has reached position 10
  120. fseek ($fp,30,SEEK_CUR);
  121. //Move the file pointer backward 30 characters
  122. echo ftell($fp)."
    ";
  123. //After moving the file 30 characters, it reaches 40 Position
  124. echo fread($fp,10)."
    ";
  125. //Read characters between 40 and 50, the pointer will reach 50
  126. fseek($fp,-10,SEEK_END);
  127. // Set the pointer to the 10th position from the bottom of the file
  128. echo fread($fp,10)."
    ";
  129. //Output the last 10 characters of the file
  130. rewind($fp);
  131. //Set the file pointer To the beginning of the file
  132. echo ftell($fp);
  133. //The file pointer returns to the beginning, so 0
  134. fclose($fp);
  135. ?>
Copy code

PHP


Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Hot Topics

Java Tutorial
1664
14
PHP Tutorial
1268
29
C# Tutorial
1246
24
PHP and Python: Comparing Two Popular Programming Languages PHP and Python: Comparing Two Popular Programming Languages Apr 14, 2025 am 12:13 AM

PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.

PHP in Action: Real-World Examples and Applications PHP in Action: Real-World Examples and Applications Apr 14, 2025 am 12:19 AM

PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.

Explain secure password hashing in PHP (e.g., password_hash, password_verify). Why not use MD5 or SHA1? Explain secure password hashing in PHP (e.g., password_hash, password_verify). Why not use MD5 or SHA1? Apr 17, 2025 am 12:06 AM

In PHP, password_hash and password_verify functions should be used to implement secure password hashing, and MD5 or SHA1 should not be used. 1) password_hash generates a hash containing salt values ​​to enhance security. 2) Password_verify verify password and ensure security by comparing hash values. 3) MD5 and SHA1 are vulnerable and lack salt values, and are not suitable for modern password security.

PHP: A Key Language for Web Development PHP: A Key Language for Web Development Apr 13, 2025 am 12:08 AM

PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7

How does PHP handle file uploads securely? How does PHP handle file uploads securely? Apr 10, 2025 am 09:37 AM

PHP handles file uploads through the $\_FILES variable. The methods to ensure security include: 1. Check upload errors, 2. Verify file type and size, 3. Prevent file overwriting, 4. Move files to a permanent storage location.

How does PHP type hinting work, including scalar types, return types, union types, and nullable types? How does PHP type hinting work, including scalar types, return types, union types, and nullable types? Apr 17, 2025 am 12:25 AM

PHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values ​​and handle functions that may return null values.

The Enduring Relevance of PHP: Is It Still Alive? The Enduring Relevance of PHP: Is It Still Alive? Apr 14, 2025 am 12:12 AM

PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.

PHP vs. Python: Understanding the Differences PHP vs. Python: Understanding the Differences Apr 11, 2025 am 12:15 AM

PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.

See all articles