The CHANGE (C) command is used in the Edit mode to replace a specific string or pattern within a dataset or member. This command is particularly useful for editing large datasets where manual changes would be time-consuming.

Key Features -

• String Replacement: Replaces one string with another throughout a dataset or within a specified range.
• Flexible Search Criteria: Specify column ranges, case sensitivity, or labels to restrict the change scope.
• Global Changes: Replace multiple occurrences in one execution.
• Undo Support: Changes can be undone using the UNDO command if SETUNDO is enabled.

Syntax -

C 'old-string' 'new-string' [range] [column-range] [options]

Parameters -

Parameter	Description
old-string	The string to be replaced.
new-string	The string to replace with.
range	Specifies the line range (e.g., .A .B for label range, or 5 10 for line numbers).
column-range	Restricts the change to specified columns (e.g., 10 20).
options	Additional flags like FIRST, ALL, PREFIX, SUFFIX, WORD, CHAR, etc., to refine the search.

Common Options -

• FIRST: Changes only the first occurrence in each line.
• ALL: Changes all occurrences in the specified range.
• PREFIX: Matches strings that start with the specified string.
• SUFFIX: Matches strings that end with the specified string.
• WORD: Changes only complete words that match the old-string.
• CHAR: Allows changes of substrings (default behavior).

Examples -

Scenario - Change "HELLO" in the program to "HI".
The changed line highlighted in red from first 1 to 6 columns and cursor will be placed after the first changed text.

More Examples -

Command	Function
C 'OLD' 'NEW'	Replaces the first occurrence of OLD with NEW in each line of the dataset.
C 'OLD' 'NEW' ALL	Replaces all occurrences of OLD with NEW in the entire dataset.
C 'DATA' 'INFO' 5 10	Replaces DATA with INFO between lines 5 and 10.
C C'TEST' 'EXAM'	Replaces TEST with RESULT within columns 1 to 20 in all lines.
C 'ERROR' 'SUCCESS' .A .B	Replaces ERROR with SUCCESS in the lines between labels .A and .B.
C PREFIX'ABC' 'XYZ'	Replaces strings starting with ABC with XYZ.
C SUFFIX'END' 'FINISH'	Replaces strings ending with END with FINISH.
C P'.' X'00'	Change all invalids to hex X'00'.
C ALL 73 80 P'=' " "	Blank out everything in cols 73-80.
C ALL P'-' 1 10 "0"	Change all non-numeric chars to '0' in cols 1-10
C ALL P'#' " " 20 25	Changes all numeric character between column 20 to 25

---