SAS/C Library Reference, Vol. 1

quiet -- Control Library Diagnostic Output

SYNOPSIS

 #include <lclib.h>

 void quiet(int flag);

DESCRIPTION

quiet suppresses library diagnostics or allows them to be produced. A nonzero argument requests message suppression, and a 0 argument allows diagnostics to be printed (if they have not been suppressed by other active functions).

quiet operates on a function-by-function basis. If any active function calls quiet(1) and does not reset it by calling quiet(0), diagnostics are suppressed. (Thus, a function cannot countermand a quiet(1) issued by its caller. Also note that quiet(1) has no effect after the function that calls it has terminated.)

You can suppress diagnostics for the entire execution of a program if main issues quiet(1) during start-up. If you want to suppress messages in coprocesses, be sure that the initial main function within each coprocess contains a call to quiet. Calling the quiet function within the main function of a program that subsequently creates coprocesses does not suppress messages within the new coprocess. See Chapter 9, "Coprocessing Functions" in the SAS/C Library Reference, Volume 2 for more information on coprocesses.

If the library option =warning is specified at run time, calls to quiet have no effect. (See Chapter 9, "Run-Time Argument Processing," in the SAS/C Compiler and Library User's Guide, Fourth Edition for more information about =warning.)

RETURN VALUE

quiet has no return value.

CAUTION

You should use quiet only when a message would be issued by the library for a harmless condition, or in which the caller can generate a more informative message for all possible warning conditions.

EXAMPLE

  #include <lclib.h>
  #include <stdio.h>

  main()
  {
     FILE *f;
     quiet(1);                     /* Suppress library messages. */
     f = fopen("ddn:SYSLIN", "r"); /* Try to open SYSLIN.        */
     quiet(0);                     /* Allow messages again,      */
     if (!f){                      /* or use SYSIN as a backup.  */
        puts("Unable to open SYSLIN, using SYSIN instead.");
        f = fopen("ddn:SYSIN", "r");
     }
  }

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