# USPSBS
> [HTML Version](uspsbs_sbr.htm)
_Updated January 2013; see History_
**xcall USPSBS, trackstr, routestr, barstr, status**
USPSBS creates an encoded bar string for the US Post Office intelligent bar codes.
**Parameters**
_trackstr _([String](string.htm.md), 21) \[in\]
tracking string
_routestr _([String](string.htm.md), 12) \[in\]
route string
_barstr _([String](string.htm.md), 66) \[out\]
returned encoded bar string. It is a character format equivalent of the graphic bar code, designed to be easy to convert to the graphic format. See the documentation on the USPS web page for specifications.
_status _(F) \[out\]
returned status code per the following table:
| **Value** | **Description** |
|------|------|
| 0 | Sucess |
| \-1 | Parameter error |
| \-2 | Unable to load usps4cb.dll |
| \-3 | Unable to locate the USPS4CB() function |
| \-99 | Not supported on current platform |
| \>0 | invalid _trackstr_ and/or _routestr_ |
**Comments**
The file usps4cb.dll is available from the US Postal Service's [Intelligent Mail Barcode Resource Download Site](https://ribbs.usps.gov/index.cfm?page=intellmailmailpieces#_blank) and must be saved somewhere in the path or in the A-Shell bin directory.
See the publications on the above web site for details on creating the _trackstr _and _routestr _values.
See [EXLIB:\[908,52\]](https://bitbucket.org/microsabio/exlib/src/master/908052/) for sample and test programs.
**History**
2013 January, A-Shell 6.1.1331: support added for Unix (routine previously was for Windows only)
2011 January, A-Shell 5.1.1201: added to A-Shell