COBOL COPY Statement

Code Example

## COBOL COPY Statement

The COPY statement inserts prewritten code (copybooks) into a program at compile time. It promotes code reuse and standardization.

### Syntax

\`\`\`cobol
COPY copybook-name [OF/IN library-name]
    [REPLACING ==pseudo-text-1== BY ==pseudo-text-2==]
    [REPLACING identifier-1 BY identifier-2].
\`\`\`

### Common Uses

1. **Record layouts**: File and database record structures
2. **Standard fields**: Common data definitions
3. **Paragraphs**: Reusable processing logic
4. **Constants**: Standard values and literals

### REPLACING Clause

Allows modification of copied text:
- Replace field names for different contexts
- Change prefixes for multiple file definitions
- Modify literals or values

### Best Practices

- Keep copybooks in a central library
- Use meaningful, standardized names
- Document copybook contents
- Version control copybooks
- Minimize use of REPLACING (can obscure code)

### Copybook Locations

In JCL, copybooks are specified via SYSLIB DD statement in compile step.