/

Displays, and in some cases prompts you to modify, the value of (any part of) a variable, including (where appropriate) a symbol, a particular dimensioned array element, dynamic array field, and substring. Multiple values can also be displayed, but apart from array elements these cannot be modified.

Syntax

These forms of the / command allow you to display and modify the variables:

{X} / variable-name{<attr#{,value# {,subvalue#}}>} {[start#{,length}]}

{X} / vector-name(row){<attr#{,value# {,subvalue#}}>} {[start#{,length}]}

{X} / vector-name(row)*

{X} / matrix-name(row{,column}){<attr#{,value# {,subvalue#}}>} {[start#{,length}]}

{X} / matrix-name(row{,column})*

These forms of the / command allow you only to display the variables:

{X} / *

{X} / * {V}{D}{E}

{X} / vector-name(start-row)-(end-row)

{X} / matrix-name(start-row{,start-column})-(end-row{,end-column})

This form of the / command allows you to display the symbol value and (where applicable) modify the variable or array element to which it equates (if any):

{X} / symbol-name

Syntax elements

variable-name A simple variable.

vector-name A one-dimensional array.

matrix-name A two-dimensional array.

symbol-name A symbol identifier.

att# Attribute offset.

value# Value offset within an attribute.

sub-value# Sub-value offset within a value.

start Substring start offset.

length Length of a substring (in characters).

row A row number in a dimensioned array.

column A column number in a dimensioned array.

start-row The first row number of a range of vector or matrix elements.

end-row The last row number of a range of vector or matrix elements.

start-column The first column number of a range of matrix elements.

end-column The last column number of a range of matrix elements.

*When applied to a vector, * displays the whole vector starting at the specified row.

When applied to a matrix, * displays the whole matrix starting at the specified row and column.

On its own, /* displays all the simple variables and dimensioned arrays, unless filtered by V, D or E.

V Displays all simple variables.

D Displays all dimensioned arrays (vectors and matrices).

E Displays all symbol equates.

Option

X Specifies that the display and input will be in hexadecimal. X precedes the command.

Displaying variables

For simple variables and arrays, the system displays the value, followed by an equal sign (=) if the form of the command allows you to modify it. The = is a prompt to input a new value.

For symbols, the system displays the value and, if it equates to a simple variable or array element, prompts you to enter * to view that variable or element, which you can then modify if required.

If there is no current value for the variable, the system displays the value as <undefined>.

If you use a variable name not found in the program, the debugger displays:

Symbol not found.

If you use the / command and did not first compile a symbol table, the following message is displayed:

No symbol table.

Note

The / command performs a case-sensitive search of the symbol table for the variable you entered. If a matching entry is found, its value is displayed. Otherwise, it next performs a case-insensitive search:

  • If only one entry is found, its value is displayed.

  • If more than one entry is found, the Symbol not found  message is displayed.

Modifying variables

At the = prompt, press RETURN to return to the debugger prompt. The value of the variable remains unchanged.

At the = prompt, you can type in a new value for the variable. The new value remains in effect during further program execution until it is assigned a new value by the program. For example:

*/CITY   ROME=PARIS

This command displays the value of variable CITY which is ROME. The value is changed to PARIS by typing the new value after the equals sign.

If you enclose the new value in single or double quotes, these will be removed before assignment to the variable or array element. For example:

*/CITY   ROME="PARIS"
*/CITY   PARIS=

To include the enclosing quotes as part of the value, enclose the value in two pairs of quotes:

*/CITY   ROME=""PARIS""
*/CITY   "PARIS"=

To set a variable or array element to a null string, use just a pair of double or single quotes:

*/CITY   ROME=""
*/CITY   =

Note

  • Only the outer matching pair of quotes is removed. Any other quotes remain unchanged.

  • Although all the above examples use double quotes, they could just as well have used single quotes.

Arrays

For a dimensioned array, the form of the command determines whether values in the array can be modified, as described above.

Pressing RETURN displays the next element of the array. Press BREAK (CTRL+BREAK on some terminals) to discontinue displaying each array element and to return to the debugger prompt.

Substrings

If you specify only a single value in the substring specification, it is interpreted as a negative offset and a positive length. For example [6] is equivalent to [-6,6].

Symbols

The symbol itself cannot be modified, but if the symbol is a symbolic link to a variable or array element, the system prompts you to enter * to view that variable or element. Once the referenced variable or element is displayed, the usual = prompt allows you to modify its value.

In the following example the version symbol equates to the item(1) vector element whose value is changed from 1 to 2 (as confirmed by displaying both again):

*/version EQU TO {ITEM(1)  } enter '*' to view:*
/ITEM(1)    1=2

*/version EQU TO {ITEM(1)  } enter '*' to view:*
/ITEM(1)    2=¿

*/item(1) 2=¿

Character and hexadecimal values

If the display is in hexadecimal, any input is assumed to be in hexadecimal. If the display is in character format, any input is assumed to be in character format.

If the display is in character format, a hexadecimal value can be input by typing a (.) followed by the two-character ASCII hexadecimal equivalent of the desired character. The (.) must be typed prior to each hexadecimal character.

Type CTRL+D at the = prompt to redisplay the value in another format. If the display is in hexadecimal, CTRL+D redisplays the value in character format and if the display is in character format, CTRL+D redisplays the value in hexadecimal format.

Operation

Any system delimiters contained in a displayed variable are changed to printable characters. All other control characters are converted to tildes (~). Because this conversion also takes place when a statement is executed by single-stepping with the debugger, the display is not interrupted by program-generated cursor control.

Examples

*/HOURS

Displays the value of the variable HOURS.

*/ITEM<3,2,1>

Displays the first subvalue in the second value in the third attribute of the dynamic array ITEM.

*/FILES(3,6)<1,4,2>

Displays the second subvalue in the fourth value in the first attribute held in the third row of the sixth column of the dimensioned array FILES.

*/NAME

Displays the value of every element in vector NAME (implicitly starting at the first element).

*/NAME(3)

Displays the value of the third element in the vector NAME.

*/NAME(3)*

Displays the value of every element in the vector NAME, starting at the third element.

*/NAME(3)-(7)

Displays the value of every element in vector NAME, starting at the third element and ending at the seventh element (inclusive) but does not allow you to modify them.

*/GRID

Displays the value of every element in the matrix GRID (implicitly starting at the first element).

*/GRID(4,5)

Displays the value in the fourth row and fifth column in the matrix GRID.

*/GRID(4,5)*

Displays the value of every element in the matrix GRID, starting at the fourth row, fifth column.

*/GRID(4,5)-(8,9)

Displays the value of every element in the matrix GRID, starting at the fourth row and fifth column, and ending at the eighth row and ninth column (inclusive) but does not allow you to modify them.

*/*

Displays the values of all the variables in the program but does not allow you to modify them.