Quick Reference¶

A condensed lookup for the things you reach for constantly. For explanations, follow the links back to the relevant chapter.

Data types¶

Type	For	Max / note
`CHAR(n)`	Fixed-length text	up to 32,767
`VARCHAR(n)`	Variable-length text	up to 32,767
`STRING`	Variable-length text	up to 32,767
`TEXT`	Long / unlimited text	blob
`INTEGER`	Whole number	32-bit
`SMALLINT`	Whole number	16-bit
`DECIMAL(p,s)`	Exact decimal (money!)	`p` digits, `s` decimals
`MONEY(p,s)`	Currency amount
`FLOAT`	Approximate decimal	avoid for money
`DATE`	Calendar date	shown per `DBDATE`
`DATETIME`	Date + time

Operators¶

arithmetic   +  -  *  /  MOD
compare      =  !=  <  <=  >  >=
logic        AND  OR  NOT
null         IS NULL      IS NOT NULL
text match   MATCHES "J*"   LIKE "John%"
concatenate  a CLIPPED, " ", b CLIPPED      a || b

Control flow¶

IF cond THEN ... ELSE ... END IF

CASE value
    WHEN x ...
    OTHERWISE ...
END CASE

WHILE cond ... END WHILE
FOR i = 1 TO n [STEP s] ... END FOR
FOREACH cursor INTO vars ... END FOREACH

EXIT FOR | EXIT WHILE | CONTINUE FOR

Functions¶

FUNCTION name(a, b)
    DEFINE a INTEGER
    DEFINE b INTEGER
    RETURN a + b
END FUNCTION

CALL name(2, 3) RETURNING result
CALL do_something()                 -- returns nothing

Built-in functions¶

Text

Call	Result
`LENGTH(s)`	Length of `s`
`UPSHIFT(s)`	Uppercase
`DOWNSHIFT(s)`	Lowercase
`instr(s, sub)`	Position of `sub` in `s` (0 if none)
`s[a,b]`	Substring from `a` to `b`
`s CLIPPED`	`s` with trailing spaces removed
`ASCII n` / `CHR(n)`	Character ↔ code

Numbers

Call	Result
`ABS(x)`	Absolute value
`ROUND(x, n)`	Round to `n` decimals
`TRUNC(x, n)`	Truncate
`x MOD y`	Remainder

Dates

Call	Result
`TODAY`	Today's date
`CURRENT`	Current date and time
`YEAR(d)` / `MONTH(d)` / `DAY(d)`	Parts of a date
`WEEKDAY(d)`	Day of week (0 = Sunday)
`MDY(m, d, y)`	Build a date
`d + 30`	30 days later
`end - start`	Days between

Formatting

LET text = amount USING "###,##&.&&"     -- number with separators
LET text = order_date USING "yyyy-mm-dd" -- date as text

Program / system

Call	Result
`NUM_ARGS()`	Number of command-line args
`ARG_VAL(i)`	The `i`-th argument
`fgl_getenv("VAR")`	An environment variable

Screens and lists¶

OPEN WINDOW w WITH FORM "name"      CLOSE WINDOW w
DISPLAY BY NAME var, var2           DISPLAY value TO field
INPUT BY NAME var, var2 [WITHOUT DEFAULTS]
MENU "title" COMMAND "X" ... EXIT MENU END MENU

CALL SET_COUNT(n)
DISPLAY ARRAY a TO sr.* ... END DISPLAY
INPUT ARRAY a FROM sr.* ... END INPUT
ARR_CURR()                          -- current row number

Status flags:

Flag	Meaning
`INT_FLAG`	True if the user cancelled
`SQLCA.SQLCODE`	`0` ok, `100` not found, `<0` error
`STATUS`	Result of the last non-SQL operation

SQL¶

DATABASE db
SELECT cols INTO vars FROM t WHERE ...
DECLARE c CURSOR FOR SELECT ...      FOREACH c INTO vars ... END FOREACH
INSERT INTO t (...) VALUES (...)
UPDATE t SET col = val WHERE ...
DELETE FROM t WHERE ...
PREPARE p FROM "... ?"               EXECUTE p USING v INTO out
BEGIN WORK    COMMIT WORK    ROLLBACK WORK
WHENEVER ERROR STOP|CONTINUE         WHENEVER NOT FOUND CONTINUE

VDC client calls¶

CALL ui.Interface.setText("Title")
CALL ui.Interface.loadStyles("default")

DEFINE w ui.Window  DEFINE f ui.Form
LET w = ui.Window.getCurrent()   LET f = w.getForm()
CALL f.setFieldHidden("field", 1)        -- 1 hide, 0 show

DEFINE cb ui.ComboBox
LET cb = ui.ComboBox.forName("field")    CALL cb.clear()
CALL cb.addItem("value", "Label")

CALL ui.vdc.toast("Saved", 0, 3000)      -- type 0=ok 1=error 2=warn 3=info

Build commands¶

4glpc -o prog.4ae prog.4gl                 # single file
4glpc -o app.4ae  a.4gl b.4gl c.4gl        # multi-file (globals first)
4glc  -o mod.ao   mod.4gl                   # one module to an object
4glpc -o app.4ae  *.ao                      # link objects
fcompile -xml form.per                      # a form
4glc --as-dll -o lib.so a.4gl b.4gl         # a shared library
./prog.4ae                                  # run

Environment variables¶

export AUBITDIR=/opt/aubit4gl
export PATH=$AUBITDIR/bin:$PATH
export LD_LIBRARY_PATH=$AUBITDIR/lib:$LD_LIBRARY_PATH

export A4GL_UI=XML                 # speak the VDC protocol
export AFGLSERVER=127.0.0.1        # where the client listens
export AFGLPORT=3490               # the client's port

export DBPATH=.:/path/to/forms     # where forms are found
export DBDATE=DMY4/                # date display, e.g. 31/12/2026
export DB_LOCALE=en_US.UTF-8
export CLIENT_LOCALE=en_US.UTF-8

The gotchas, in one place¶

DEFINE statements go at the top of a function, before any code.
Test empty text with LENGTH(x CLIPPED) > 0, not x != "".
STRING has no methods — use instr, x[a,b], UPSHIFT, DOWNSHIFT, CLIPPED.
You cannot pass an array as a parameter — use COPYOF (read-only) or a global array.
There is no TRY/CATCH and no ELSE IF (two words) — check status, and use CASE.

That is the everyday toolkit. For the exhaustive lists, see the Language Reference (every statement and built-in) and the Command-line Tools page. The fastest way to learn, though, is to type the examples in, compile them, and change them until they break — then fix them.