Using FSCAN

When you enter FSCAN, FSCAN displays as much as it can of the root segment of the data source. For example, if you view the EMPLOYEE data source with FSCAN, using the following command

FSCAN FILE EMPLOYEE

you will see the following screen:

 
1. FSCAN FILE   EMPLOYEEFOCUS   A1              CHANGES:     0
  
2. EMP_ID        LAST_NAME     FIRST_NAME     HIRE_DATE      DEPARTMENT
   ------        ---------     ----------    ---------  ---------- 
3. == 071382660  STEVENS       ALFRED         800602         PRODUCTION 
4. == 112847612  SMITH         MARY           810701         MIS
   == 117593129  JONES         DIANE          820501         MIS
   == 119265415  SMITH         RICHARD        820104         PRODUCTION
   == 119329144  BANNING       JOHN           820801         PRODUCTION
   == 123764317  IRVING        JOAN           820104         PRODUCTION
   == 126724188  ROMANS        ANTHONY        820701         PRODUCTION
   == 219984371  MCCOY         JOHN           810701         MIS
   == 326179357  BLACKWOOD     ROSEMARIE      820401         MIS
   == 451123478  MCKNIGHT      ROGER          820202         PRODUCTION
   ------------------------------INPUT--------------------------------- 
5. == 
6. ==> 
7.                                                              MORE=>

This screen displays the contents of the root segment of the EMPLOYEE database. Each record on the screen is one instance in the root segment. The numbers in the diagram refer to the notes below:

The header shows the name of the database and the number of changes made to the database since the last save.
Each field is labeled with a column heading.
The first record at the top of the screen is called the current instance. Many commands operate only on this record. When you first enter FSCAN, this record is the first instance in the root segment.
The equal signs (==) in the left margin of the screen indicate the prefix area. This is where you enter prefix area commands.
The key field value in each record appears highlighted.
The last line with equal signs is called the input area and is reserved exclusively for input.
The arrow at the lower-left corner of the screen points to the command line. This is where you enter FSCAN commands.
The MORE symbol at the lower-right corner of the screen indicates that each record extends to the right of the screen.

This section discusses various functions of the FSCAN facility. For an alphabetic summary of commands, see Syntax Summary.

The FSCAN facility displays one segment at one time. (For the root segment, FSCAN displays all instances in the segment; for descendant segments, FSCAN displays all instances sharing the same parent instance.) Each record on the screen is one segment instance. The first instance at the top of the screen is called the current instance.

The FSCAN facility also displays segments in SINGLE mode, that is, one instance at one time. SINGLE mode is discussed in Displaying a Single Instance on One Screen: The SINGLE and MULTIPLE Commands.

Note the different types of commands:

Prefix area commands are typed in the prefix area on the left of the screen display. Prefix area commands operate only on the line where they are typed.
Command-line commands are typed on the command line at the bottom of the screen. Some commands operate on the entire screen, others operate only on the current instance at the top of the screen. There are two types of command-line commands:
- Immediate commands. When you execute an immediate command, the database remains unchanged even if you typed changes on the screen. There are five immediate commands:
```
LEFT
RIGHT
RESET
?
QQUIT
```
- Non-immediate commands. When you execute a non-immediate command, any changes you type on the screen will be written to the database even if the command itself does not modify the database.

The following rules apply to commands:

You may use unique truncations for commands. When this section specifies a command syntax, the unique truncation is shown in uppercase.
Commands that use field names as parameters require the full field name, alias, or unique truncation.
You may enter two commands at one time by separating the commands with a semicolon. For example, to enter the commands NEXT 5 and CHILD at one time, type:
```
NEXT 5; CHILD
```