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    Copyright
    Preface
    Ch. 1. Strings
    Ch. 2. Numbers
    Ch. 3. Dates and Times
    Ch. 4. Arrays
    Ch. 5. Variables
    Ch. 6. Functions
    Ch. 7. Classes and Objects
    Ch. 8. Web Basics
    Ch. 9. Forms
    Ch. 10. Database Access
    Ch. 11. Web Automation
    Ch. 12. XML
    Ch. 13. Regular Expressions
    Ch. 14. Encryption and Security
    Ch. 15. Graphics
    Ch. 16. Internationalization and Localization
    Ch. 17. Internet Services
    Ch. 18. Files
    Introduction
    Recipe 18.2. Creating or Opening a Local File
    Recipe 18.3. Creating a Temporary File
    Recipe 18.4. Opening a Remote File
    Recipe 18.5. Reading from Standard Input
    Recipe 18.6. Reading a File into a String
    Recipe 18.7. Counting Lines, Paragraphs, or Records in a File
    Recipe 18.8. Processing Every Word in a File
    Recipe 18.9. Reading a Particular Line in a File
    Recipe 18.10. Processing a File Backward by Line or Paragraph
    Recipe 18.11. Picking a Random Line from a File
    Recipe 18.12. Randomizing All Lines in a File
    Recipe 18.13. Processing Variable Length Text Fields
    Recipe 18.14. Reading Configuration Files
    Recipe 18.15. Reading from or Writing to a Specific Location in a File
    Recipe 18.16. Removing the Last Line of a File
    Recipe 18.17. Modifying a File in Place Without a Temporary File
    Recipe 18.18. Flushing Output to a File
    Recipe 18.19. Writing to Standard Output
    Recipe 18.20. Writing to Many Filehandles Simultaneously
    Recipe 18.21. Escaping Shell Metacharacters
    Recipe 18.22. Passing Input to a Program
    Recipe 18.23. Reading Standard Output from a Program
    Recipe 18.24. Reading Standard Error from a Program
    Recipe 18.25. Locking a File
    Recipe 18.26. Reading and Writing Compressed Files
    Recipe 18.27. Program: Unzip
    Ch. 19. Directories
    Ch. 20. Client-Side PHP
    Ch. 21. PEAR
    Colophon
    Index
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    Help

    Chapter 18. Files > Reading Standard Error from a Program

    Recipe 18.24. Reading Standard Error from a Program

    18.24.1. Problem

    You want to read the error output from a program; for example, you want to capture the system calls displayed by strace(1) .

    18.24.2. Solution

    Redirect standard error to standard output by adding 2>&1 to the command line passed to popen( ). Read standard output by opening the pipe in r mode:


      

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