---
name: "GetDash"
section: "3tk"
platform: "linux"
package: "tk8.3-doc"
version: "8.3.5-14"
release: "Debian 5.0 (Lenny)"
platforms: ["linux"]
url: "https://new.carta.tech/GetDash/3tk"
---

# GetDash(3tk)

convert from string to valid dash structure.

```

```

## NAME

Tk\_GetDash - convert from string to valid dash structure.

## SYNOPSIS

```
#include <tk.h>

int
Tk_GetDash(interp, string, dashPtr)
```

## ARGUMENTS

- Tcl\_Interp *\*interp* (in)

  Interpreter to use for error reporting.

- CONST char \* *string* (in)

  Textual value to be converted.

- Tk\_Dash *\*dashPtr* (out)

  Points to place to store the dash pattern value converted from *string*.

  ```

  ```

## DESCRIPTION

These procedure parses the string and fills in the result in the Tk\_Dash structure. The string can be a list of integers or a character string containing only **\[.,-\_\]** or spaces. If all goes well, TCL\_OK is returned. If *string* doesn't have the proper syntax then TCL\_ERROR is returned, an error message is left in the interpreter's result, and nothing is stored at \**dashPtr*.

The first possible syntax is a list of integers. Each element represents the number of pixels of a line segment. Only the odd segments are drawn using the "outline" color. The other segments are drawn transparent.

The second possible syntax is a character list containing only 5 possible characters **\[.,-\_ \]**. The space can be used to enlarge the space between other line elements, and can not occur as the first posibion in the string. Some examples:\
     \-dash .     = -dash {2 4}\
     \-dash -     = -dash {6 4}\
     \-dash -.    = -dash {6 4 2 4}\
     \-dash -..   = -dash {6 4 2 4 2 4}\
     \-dash {. }  = -dash {2 8}\
     \-dash ,     = -dash {4 4}

The main difference of this syntax with the previous is that it it shape-conserving. This means that all values in the dash list will be multiplied by the line width before display. This assures that "." will always be displayed as a dot and "-" always as a dash regardless of the line width.

On systems where only a limited set of dash patterns, the dash pattern will be displayed as the most close dash pattern that is available. For example, on Windows only the first 4 of the above examples are available. The last 2 examples will be displayed identically as the first one.

## KEYWORDS

dash, conversion