Swat Introduction: 6 Additional Features

GEOS SDK TechDocs

5 Essential Commands

This section covers the features of Swat that make it easier to use when debugging an application.

• Mouse support
  You can use the mouse to capture and paste text in the main Swat buffer. Capture text by click-dragging with the left mouse button. Pressing the right mouse button pastes the captured text to the Swat prompt line.
• Navigating the Main Buffer
  To scroll the main buffer, use Ctrl-u (up), Ctrl-d (down), Ctrl-y (back one line), Ctrl-e (forward one line), Ctrl-b (backward page) and Ctrl-f (forward page).
• Command History
  By pressing Ctrl-p several times, you can call previous commands up to the Swat prompt. If you go past the command that you want, use Ctrl-n to go forward in the history.
  The `!' character followed by a number repeats that command in the command history. (The standard Swat prompt includes a command number which may be used for this.) e.g. !184 will execute the 184th command of this session.
  The `!' character followed by a string will repeat the most recent command whose beginning is the same as the passed string. That is !b might invoke brk list if that was the most recent command that began with "b".
  Typing "!!" will repeat the previous command; "!$" is the last argument of the previous command.
• Command Correction
  To repeat the previous command, but changing a piece of it, use the ^ command. This comes in handy when you've made a typo trying to enter the previous command.

Swat Display 3-14 Command Correction Using ^

(geos:0) 185 => wurds
Error: invoked "wurds", which isn't a valid command name

(geos:0) 186 => ^u^o
words
Addr:	 	 +0   +2   +4   +6   +8   +a   +c   +e
4b4bh: e800 01b1 0e00 60f6 0016 9800 6e02 a900

(geos:0) 187 => ddwords
Error: invoked "ddwords", which isn't a valid command name

(geos:0) 188 => ^d
dwords
Addr:  +0       +4       +8       +c
4b59h: 1d0aa900 001c400d 294bd000 6c0a8000

• Address History
  Swat has an address history which is composed of tokens for address expressions previously used by commands such as print or pobj . The elements in the history can be accessed by typing @<number> where the number argument is the number of the item in the history. These elements can replace a full address expression (except constants) and are often used when traversing through fields of a previously printed structure. The default history keeps track of the last 50 items. (See The Address History .)

Swat Display 3-15 The Address History

(geos:0) 8 => gentree -i
GenPrimaryClass (@1, ^l44a0h:001eh) "MESS #1"
 GenViewClass (@2, ^l44a0h:0020h)
 GenValueClass (@3, ^l44a0h:0026h)
 GenValueClass (@4, ^l44a0h:0028h)

(geos:0) 9 => pinst @3
class = ui::dgroup::GenValueClass
master part: Gen_offset(53) -- ui::GenValueInstance
@5: {ui::GenValueInstance (^h17568:1170)+53} = {
 GenInstance GenValue_metaInstance = {
 MetaBase Gen_metaInstance = {
 ClassStruct _far *MB_class = 3573h:1867h (motif::dgroup::OLScrollbarClass)
 }
 LinkPart GI_link = {
 void _optr LP_next = ^l44a0h:0028h (ui::dgroup::GenValueClass@6244h:02deh)
 }
 CompPart GI_comp = {
 void _optr CP_firstChild = null
 }
 void _lptr GI_visMoniker = null
 KeyboardShortcut GI_kbdAccelerator = {
 KS_PHYSICAL = 0
 KS_ALT = 0
 KS_CTRL = 0
 KS_SHIFT = 0
 KS_CHAR_SET = 0
 KS_CHAR = C_NULL
 }
 GenAttrs GI_attrs = {}
 GenStates GI_states = {GS_USABLE, GS_ENABLED}
 }
 WWFixed GVLI_value = {0.000000}
 WWFixed GVLI_minimum = {0.000000}
 WWFixed GVLI_maximum = {0.007324}
 WWFixed GVLI_increment = {0.000229}
 GenValueStateFlags GVLI_stateFlags = {GVSF_INDETERMINATE}
 GenValueDisplayFormat GVLI_displayFormat = GVDF_INTEGER
 void _optr GVLI_destination = ^l44a0h:0020h (ui::dgroup::GenViewClass@6244h:01aah)
 word GVLI_applyMsg = 681ah
} 
(geos:0) 10 =>

• Abbreviations
  Another shortcut available in Swat is the abbreviation feature. Many commands can be specified by their first few characters up to and including the letter that makes them distinct from all other commands. For example, the pobject command can be specified pobj , pob , or even po , but not by just p because there are other commands (such as print ) beginning with the letter p . To get a list of all commands with a given prefix, type the prefix at the Swat prompt, then type Ctrl-D. To automatically complete a command name use the Escape key (if the prefix is unambiguous) or Ctrl-] to scroll through the list of possible command completions.
• Initialization Files
  If there are certain Swat commands that always need to be executed when Swat is run, then they can be placed in an initialization file. (See An Initialization File srcwin 15 regwin save 500 patient-default mess1 run ) An initialization file contains a list of commands that will be executed just before the first prompt in Swat.
  The initialization file should be called SWAT.RC. Swat will look in the directory from which it was invoked for such a file. If it doesn't find one there, it will look for a file named SWAT.RC in a directory named in the HOME environment variable

Swat Display 3-16 An Initialization File

srcwin 15 
regwin
save 500
patient-default mess1
run

This example shows a sample initialization file which sets up windows to display the source code and current register values, set the length of the save buffer to 500 lines, and continue running swat until the mess1 application has been loaded, at which point execution will automatically stop.

GEOS SDK TechDocs

5 Essential Commands