[Chapter 15] 15.3 Displaying Source Code Chapter 15PLVvu: Viewing Source Code and Compile Errors 15.3 Displaying Source CodePLVvu provides two procedures to display source code: the code and code_after programs. The code program displays all the lines of code for the specified program unit found between the start and end lines specified. The code_after program displays the specified number of lines found after the n th occurrence of a particular string. They are both explained below.15.3.1 Displaying Code by Line NumberThe header for the code program is:PROCEDURE code (name_in IN VARCHAR2 := NULL, start_in IN INTEGER := 1, end_in IN INTEGER := NULL, header_in IN VARCHAR2 := 'Code for');The first argument is the name of the program unit. If you do not supply a program, PLVvu.code will use the object last compiled into the database. The format for specifying a program unit is explained in Chapter 11. Briefly, you can supply only the name, the type:name (as in "b:PLVio" for the body of the PLVio package), or even the type:schema.name (as in "s:scott.showemps" to see the specification of the showemps package owned by SCOTT).The second and third arguments provide the range of line numbers of the code to be displayed. The default is all lines, with the start value of 1 and the end value NULL. The final argument provides a prefix for the output's header.If you want to see all the lines of source code for a program unit, simply pass the program name and leave all the other arguments as the default. This approach is shown below:SQL> exec PLVvu.code('s:testcase'); -------------------------------------------------------------------- Code for PACKAGE TESTCASE -------------------------------------------------------------------- Line# Source -------------------------------------------------------------------- 1 package testcase 2 is 3 procedure save (string_in in varchar2); 4 end testcase;The next call to PLVvu.code requests that it display lines 85 through 95 of the body of the PLVvu package.SQL> exec PLVvu.code ('b:PLVvu', 85, 95, 'Contents of'); ---------------------------------------------------------------------- Contents of PACKAGE BODY PLVVU ---------------------------------------------------------------------- Line# Source ---------------------------------------------------------------------- 85 THEN 86 p.l ('ERR' || LPAD ('*', err_rec.position+4)); 87 PLVprs.display_wrap 88 (PLVchr.stripped (err_rec.text, PLVchr.newline_char), 89 60, ' '); 90 END IF; 91 CLOSE err_cur; 92 END; 93 /*--------------- Public Modules -----------------*/ 94 PROCEDURE set_overlap 95 (size_in IN INTEGER := c_overlap)The code.sql SQL*Plus script allows you to skip some of the typing (and all of those irritating single quotes) when you use PLVvu.code. The last execution of PLVvu.code, for example, could be shortened to:SQL> @code b:PLVvu 85 9515.3.2 Displaying Code by KeywordThe code procedure is very useful and saves you the effort of putting together a quick SQL*Plus script to view lines of source code. However, scanning source code by line number ranges is not the only way you might want to locate and view your code. Another common method is to search for a keyword and then display the lines of code before, after, or around that keyword. The code_after procedure displays the specified lines of code appearing after the nth occurrence of a keyword you provide. The header for code_after is:PROCEDURE code_after (name_in IN VARCHAR2 := NULL, start_with_in IN VARCHAR2, num_lines_in IN INTEGER := overlap, nth_in IN INTEGER := 1)The first argument is the name of the program unit. If you do not supply a program, PLVvu.code will use the object last compiled into the database. The format for specifying a program unit is explained in Chapter 11. Briefly, you can supply only the name, the type:name (as in "b:PLVio" for the body of the PLVio package), or even the type:schema.name (as in "s:scott.showemps" to see the specification of the showemps package owned by SCOTT).The second argument supplies the string for which code_after will search. The num_lines_in argument is the number of lines after the keyword is found that will be displayed (default provided by the current value of the overlap count). The last argument, nth_in, specifies the number of occurrences to be located before displaying the subsequent lines of code.The following calls to code_after demonstrate the use of these different arguments. In the first example, I ask to see the default number of lines (5) following the first occurrence of SUBSTR. In the second call to code_after, I request to see only three lines following the fifth occurrence of SUBSTR.SQL> exec PLVvu.code_after('b:PLVio','SUBSTR'); ---------------------------------------------------------------------- Code Starting with "SUBSTR" in PACKAGE BODY PLVIO ---------------------------------------------------------------------- Line# Source ---------------------------------------------------------------------- 330 (SUBSTR (srcrep.select_sql, 1, loc-1) || 331 srcrep.where_clause || ' ' || 332 SUBSTR (srcrep.select_sql, loc)); 333 ELSE 334 RETURN srcrep.select_sql; 335 END IF; SQL> exec PLVvu.code_after('b:PLVio','SUBSTR', 3, 5); ---------------------------------------------------------------------- Code Starting with "SUBSTR" in PACKAGE BODY PLVIO ---------------------------------------------------------------------- Line# Source ---------------------------------------------------------------------- 704 SUBSTR 705 (string_repos.text_in, 706 string_repos.start_pos); 707 string_repos.start_pos :=Now you know how to use the code and code_after procedures to display your source code. Section 15.4, "Implementing PLVvu" shows you the techniques used to obtain this information.Special Notes on PLVvuCurrently PLVvu only reads from the ALL_SOURCE data dictionary view to show source text with the code and code_after procedures. You cannot, for example, redirect the "source repository" to a file. 15.2 Displaying Compile Errors15.4 Implementing PLVvu Copyright (c) 2000 O'Reilly & Associates. All rights reserved.