Advanced Bash-Scripting Guide - FAU

1 Advanced Bash-Scripting GuideTable of ContentsAdvanced Bash-Scripting in-depth exploration of the art of shell 1. 1. Shell Programming!.. 2. Starting Off With a Invoking the Preliminary 2. 3. Special 4. Introduction to Variables and Variable Variable bash Variables Are Special Variable 5. Quoting 6. Exit and Exit 7. Bash-Scripting GuideiTable of Test File test Other Comparison Nestedif/then Condition Testing Your Knowledge of 8. Operations and Related Numerical The Double-Parentheses Operator 3. Beyond the 9. Another Look at Internal Typing variables: declare or Another use for $RANDOM: generate random 10.

2 Manipulating Manipulating Manipulating strings using Further Bash-Scripting GuideiiTable of Parameter 11. Loops and Nested Loop Testing and 12. Command 13. Arithmetic 14. Recess 4. 15. Internal Commands and Job Control 16. External Filters, Programs and Basic Complex Time / Date Text Processing File and Archiving Bash-Scripting GuideiiiTable of Communications Terminal Control Math Miscellaneous 17. System and Administrative Analyzing a System 5. Advanced 18. Regular A Brief Introduction to Regular 19. Here Here 20. I/O Using Redirecting Code 21. 22.

3 Restricted 23. Process Bash-Scripting GuideivTable of ContentsChapter 24. Complex Functions and Function Local Local variables and Recursion Without Local 25. 26. List 27. 28. Indirect 30. Network 31. Of Zeros and 32. 33. 34. 35. scripting With Unofficial Shell scripting 36. Bash-Scripting GuidevTable of Interactive and non-interactive shells and Shell Tests and Comparisons: Recursion: a script calling "Colorizing" Assorted Ideas for more powerful Security Infected Shell Hiding Shell Script Writing Secure Shell Portability A Test Shell scripting Under 37.

4 bash , versions 2, 3, and bash , version bash , version bash , version bash , version bash , version bash , version bash , version 38. Bash-Scripting GuideviTable of Author's About the Where to Go For Tools Used to Produce This Software and A. Contributed B. Reference C. A Sed and Awk D. Parsing and Managing E. Exit Codes With Special F. A Detailed Introduction to I/O and I/O G. Command-Line Standard Command-Line bash Command-Line H. Important Bash-Scripting GuideviiTable of ContentsAppendix I. Important System J. An Introduction to Programmable K. L. History M. N.

5 Converting DOS Batch Files to Shell O. Analyzing Writing P. Revision Q. Download and Mirror R. To Do S. T. ASCII Bash-Scripting GuideviiiAdvanced Bash-Scripting GuideAn in-depth exploration of the art of shell scriptingVersion 1010 Mar 2014 Mendel tutorial assumes no previous knowledge of scripting or programming, yet progresses rapidly toward anintermediate/ Advanced level of instruction .. all the while sneaking in little nuggets of UNIX wisdom andlore. It serves as a textbook, a manual for self-study, and as a reference and source of knowledge on shellscripting techniques. The exercises and heavily-commented examples invite active reader participation, underthe premise that the only way to really learn scripting is to write book is suitable for classroom use as a general introduction to programming document is herewith granted to the Public Domain.

6 No copyright!DedicationFor Anita, the source of all the magicTable of ContentsPart 1. Introduction1. Shell Programming!2. Starting Off With a Invoking the Preliminary ExercisesPart 2. Basics3. Special Characters4. Introduction to Variables and Variable Variable bash Variables Are Special Variable Types5. Quoting Escaping6. Exit and Exit Status7. Test File test Other Comparison Nestedif/then Condition Testing Your Knowledge of Tests8. Operations and Related Numerical The Double-Parentheses Operator PrecedencePart 3. Beyond the Basics9. Another Look at Internal Typing variables: declare or $RANDOM: generate random integer10.

7 Manipulating Manipulating Parameter Substitution11. Loops and Nested Loop Testing and Branching12. Command Substitution13. Arithmetic Expansion14. Recess TimePart 4. Commands15. Internal Commands and Job Control Commands16. External Filters, Programs and Basic Complex Time / Date Text Processing File and Archiving Communications Terminal Control Math Miscellaneous Commands17. System and Administrative Analyzing a System ScriptPart 5. Advanced Topics18. Regular A Brief Introduction to Regular Globbing19. Here Here Strings20. I/O Using Redirecting Code Applications21. Subshells22. Restricted Shells23.

8 Process Substitution24. Complex Functions and Function Local Recursion Without Local Variables25. Aliases26. List Constructs27. Arrays28. Indirect References29. /dev /proc30. Network Programming31. Of Zeros and Nulls32. Debugging33. Options34. Gotchas35. scripting With Unofficial Shell scripting Stylesheet36. Interactive and non-interactive shells and Shell Tests and Comparisons: Recursion: a script calling "Colorizing" Assorted Security Portability Shell scripting Under Windows37. bash , versions 2, 3, and bash , version bash , version bash , version 438. Author's About the Where to Go For Tools Used to Produce This Software and DisclaimerBibliographyA.

9 Contributed ScriptsB. Reference CardsC. A Sed and Awk AwkD. Parsing and Managing PathnamesE. Exit Codes With Special MeaningsF. A Detailed Introduction to I/O and I/O RedirectionG. Command-Line Standard Command-Line bash Command-Line OptionsH. Important FilesI. Important System DirectoriesJ. An Introduction to Programmable CompletionK. LocalizationL. History CommandsM. FilesN. Converting DOS Batch Files to Shell ScriptsO. Analyzing Writing ScriptsP. Revision HistoryQ. Download and Mirror SitesR. To Do ListS. CopyrightT. ASCII TableIndexList of Tables8-1. Operator Precedence15-1. Job identifiers33-1. bash options36-1.

10 Numbers representing colors in Escape SequencesB-1. Special Shell VariablesB-2. TEST Operators: Binary ComparisonB-3. TEST Operators: FilesB-4. Parameter Substitution and ExpansionB-5. String OperationsB-6. Miscellaneous ConstructsC-1. Basic sed operatorsC-2. Examples of sed operatorsE-1. Reserved Exit CodesN-1. Batch file keywords / variables / operators, and their shell equivalentsN-2. DOS commands and their UNIX equivalentsP-1. Revision HistoryList of Examples2-1. cleanup: A script to clean up log files in /var/log2-2. cleanup: An improved clean-up script2-3. cleanup: An enhanced and generalized version of above Code blocks and I/O redirection3-2.