book

sed & awk, 2nd Edition

by Dale Dougherty, Arnold Robbins

March 1997

Intermediate to advanced

432 pages

11h 31m

English

O'Reilly Media, Inc.

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DOS VersionsOther Sources of Information About sed and awkSample Programs
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2.2.1. Scripting2.2.2. Sample Mailing List
2.3.1. Specifying Simple Instructions2.3.1.1. Command garbled2.3.2. Script Files2.3.2.1. Saving output2.3.2.2. Suppressing automatic display of input lines2.3.2.3. Mixing options (POSIX)2.3.2.4. Summary of options
2.4.1. Running awk2.4.2. Error Messages2.4.3. Summary of Options
3.2.1. The Ubiquitous Backslash3.2.2. A Wildcard3.2.3. Writing Regular Expressions3.2.4. Character Classes3.2.4.1. A range of characters3.2.4.2. Excluding a class of characters3.2.4.3. POSIX character class additions3.2.5. Repeated Occurrences of a Character3.2.6. What’s the Word? Part I3.2.7. Positional Metacharacters3.2.7.1. Phrases3.2.8. A Span of Characters3.2.9. Alternative Operations3.2.10. Grouping Operations3.2.11. What’s the Word? Part II3.2.12. Your Replacement Is Here3.2.12.1. The extent of the match3.2.13. Limiting the Extent
4.1.1. The Pattern Space
4.2.1. Grouping Commands
4.3.1. testsed4.3.2. runsed
4.4.1. Multiple Edits to the Same File4.4.2. Making Changes Across a Set of Files4.4.3. Extracting Contents of a File4.4.3.1. Extracting a macro definition4.4.3.2. Generating an outline4.4.4. Edits To Go
5.3.1. Replacement Metacharacters5.3.1.1. Correcting index entries
5.6.1. Stripping Out Non-Printable Characters from nroff Files
5.11.1. Checking Out Reference Pages
6.1.1. Append Next Line6.1.1.1. Converting an Interleaf file6.1.2. Multiline Delete6.1.3. Multiline Print
6.3.1. A Capital Transformation6.3.2. Correcting Index Entries (Part II)6.3.3. Building Blocks of Text
6.4.1. Branching6.4.2. The Test Command6.4.3. One More Case
7.4.1. Describing Your Script
7.5.1. Referencing and Separating Fields7.5.2. Field Splitting: The Full Story
7.6.1. Averaging Student Grades
7.7.1. Working with Multiline Records7.7.2. Balance the Checkbook
7.8.1. Getting Information About Files
7.11.1. Finding a Glitch
8.1.1. Conditional Operator
8.2.1. While Loop8.2.2. Do Loop8.2.3. For Loop8.2.4. Deriving Factorials
8.4.1. Associative Arrays8.4.2. Testing for Membership in an Array8.4.3. A Glossary Lookup Script8.4.4. Using split( ) to Create Arrays8.4.5. Making Conversions8.4.6. Deleting Elements of an Array
8.5.1. Multidimensional Arrays
8.6.1. An Array of Command-Line Parameters8.6.2. An Array of Environment Variables
9.1.1. Trigonometric Functions9.1.2. Integer Function9.1.3. Random Number Generation9.1.4. Pick ‘em
9.2.1. Substrings9.2.2. String Length9.2.3. Substitution Functions9.2.4. Converting Case9.2.5. The match( ) Function
9.3.1. Writing a Sort Function9.3.2. Maintaining a Function Library9.3.3. Another Sorted Example
10.1.1. Reading Input from Files10.1.2. Assigning the Input to a Variable10.1.3. Reading Input from a Pipe
10.5.1. Directing Output to a Pipe10.5.2. Working with Multiple Files
10.7.1. Make a Copy10.7.2. Before and After Photos10.7.3. Finding Out Where the Problem Is10.7.4. Commenting Out Loud10.7.5. Slash and Burn10.7.6. Getting Defensive About Your Script
11.1.1. Escape Sequences11.1.2. Exponentiation11.1.3. The C Conditional Expression11.1.4. Variables as Boolean Patterns11.1.5. Faking Dynamic Regular Expressions11.1.6. Control Flow11.1.7. Field Separating11.1.8. Arrays11.1.9. The getline Function11.1.10. Functions11.1.11. Built-In Variables
11.2.1. Common Extensions11.2.1.1. Deleting all elements of an array11.2.1.2. Obtaining individual characters11.2.1.3. Flushing buffered output11.2.1.4. Special filenames11.2.1.5. The nextfile statement11.2.1.6. Regular expression record separators (gawk and mawk)11.2.2. Bell Labs awk11.2.3. GNU awk (gawk)11.2.3.1. Command line options11.2.3.2. An awk program search path11.2.3.3. Line continuation11.2.3.4. Extended regular expressions11.2.3.5. Regular expression record terminators11.2.3.6. Separating fields11.2.3.7. Additional special files11.2.3.8. Additional variables11.2.3.9. Additional functions11.2.3.10. A general substitution function11.2.3.11. Time management for programmers11.2.4. Michael’s awk (mawk)
11.3.1. MKS awk11.3.2. Thompson Automation awk (tawk)11.3.2.1. Tawk language extensions11.3.2.2. Additional built-in tawk functions11.3.3. Videosoft VSAwk
12.1.1. BEGIN Procedure12.1.2. Main Procedure12.1.3. END Procedure12.1.4. Supporting Functions12.1.5. The spellcheck Shell Script
12.2.1. The masterindex Program12.2.2. Standardizing Input12.2.3. Sorting the Entries12.2.4. Handling Page Numbers12.2.5. Merging Entries with the Same Keys12.2.6. Formatting the Index12.2.6.1. The masterindex shell script
12.3.1. How to Hide a Special Character12.3.2. Rotating Two Parts12.3.3. Finding a Replacement12.3.4. A Function for Reporting Errors12.3.5. Handling See Also Entries12.3.6. Alternative Ways to Sort
13.1.1. Program Notes for uutot.awk
13.2.1. Program Notes for phonebill
13.3.1. Program Notes for combine
13.4.1. Program Notes for mailavg
13.5.1. Program Notes for adj
13.6.1. Program Notes for readsource
13.7.1. Program Notes for gent
13.8.1. Program Notes for plpr
13.9.1. Program Notes for transpose
13.10.1. Program Notes for m1
A.2.1. Pattern AddressingA.2.2. Regular Expression Metacharacters for sed
B.1.1. Shell Wrapper for Invoking awk
B.2.1. Records and FieldsB.2.2. Format of a ScriptB.2.2.1. Line terminationB.2.2.2. CommentsB.2.3. PatternsB.2.4. Regular ExpressionsB.2.5. ExpressionsB.2.5.1. ConstantsB.2.5.2. Escape sequencesB.2.5.3. VariablesB.2.5.4. ArraysB.2.5.5. System variablesB.2.5.6. OperatorsB.2.6. Statements and Functions
B.3.1. Format Expressions Used in printf and sprintf

Content preview from sed & awk, 2nd Edition

Using sed

There are two ways to invoke sed: either you specify your editing instructions on the command line or you put them in a file and supply the name of the file.

Specifying Simple Instructions

You can specify simple editing commands on the command line.

sed [-e] 'instruction' file

The -e option is necessary only when you supply more than one instruction on the command line. It tells sed to interpret the next argument as an instruction. When there is a single instruction, sed is able to make that determination on its own. Let’s look at some examples.

Using the sample input file, list, the following example uses the s command for substitution to replace “MA” with “Massachusetts.”

$ sed 's/MA/Massachusetts/' list
John Daggett, 341 King Road, Plymouth Massachusetts
Alice Ford, 22 East Broadway, Richmond VA
Orville Thomas, 11345 Oak Bridge Road, Tulsa OK
Terry Kalkas, 402 Lans Road, Beaver Falls PA
Eric Adams, 20 Post Road, Sudbury Massachusetts
Hubert Sims, 328A Brook Road, Roanoke VA
Amy Wilde, 334 Bayshore Pkwy, Mountain View CA
Sal Carpenter, 73 6th Street, Boston Massachusetts

Three lines are affected by the instruction but all lines are displayed.

Enclosing the instruction in single quotes is not required in all cases but you should get in the habit of always doing it. The enclosing single quotes prevent the shell from interpreting special characters or spaces found in the editing instruction. (The shell uses spaces to determine individual arguments submitted to a program; ...