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man pages section 1: User Commands

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Updated: Thursday, June 13, 2019



ckstr, errstr, helpstr, valstr - display a prompt; verify and return a string answer


ckstr [-Q] [-W width] [ [-r regexp] [...]] [-l length] 
     [-k pid [- s signal]]
/usr/sadm/bin/errstr [-W width] [-e error] [-l length] 
     [ [-r regexp] [...]]
/usr/sadm/bin/helpstr [-W width] [-h help] [-l length] 
     [ [-r regexp] [...]]
/usr/sadm/bin/valstr [-l length] [ [-r regexp] [...]] input


The ckstr utility prompts a user and validates the response. It defines, among other things, a prompt message whose response should be a string, text for help and error messages, and a default value (which are returned if the user responds with a RETURN).

The answer returned from this command must match the defined regular expression and be no longer than the length specified. If no regular expression is given, valid input must be a string with a length less than or equal to the length defined with no internal, leading or trailing white space. If no length is defined, the length is not checked.



Three visual tool modules are linked to the ckstr command. They are errstr (which formats and displays an error message on the standard output), helpstr (which formats and displays a help message on the standard output), and valstr (which validates a response).


The following options are supported:

–d default


–e error

Defines the error message as error.

–h help

Defines the help message as help.

–k pid


–l length

Specifies the maximum length of the input.

–p prompt

Defines the prompt message as prompt.


Specifies that quit will not be allowed as a valid response.

–r regexp

Specifies a regular expression, regexp, against which the input should be validated. May include white space. If multiple expressions are defined, the answer need match only one of them.

–s signal


–W width



The following operand is supported:


Input to be verified against format length and/or regular expression criteria.


Example 1 Default prompt

The default prompt for ckstr is:

example% ckstr
Enter an appropriate value [?,q]:
Example 2 Default error message

The default error message is dependent upon the type of validation involved. The user will be told either that the length or the pattern matching failed. The default error message is:

example% /usr/sadm/bin/errstr
ERROR: Please enter a string which contains no embedded,
leading or trailing spaces or tabs.
Example 3 Default help message

The default help message is also dependent upon the type of validation involved. If a regular expression has been defined, the message is:

example% /usr/sadm/bin/helpstr –r regexp
Please enter a string which matches the following pattern:

Other messages define the length requirement and the definition of a string.

Example 4 Using the quit option


Example 5 Using the valstr module


example% /usr/sadm/bin/valstr
usage: valstr [–l length] [[–r regexp] [ . . . ]] input

Exit Status

The following exit values are returned:


Successful execution.




Invalid regular expression.


User termination (quit).


See attributes(7) for descriptions of the following attributes:


See Also

signal.h(3HEAD), attributes(7)