On Tue, 18 Mar 2025 16:24:46 +1100, Michael Brown wrote:

Working in C, how do you return the RMS$_CODE symbol for any given error number as returned from any operation?

The $GETMSG system service comes to mind. I see there is a library routine LIB$SYS_GETMSG, not sure what that does that the system service call does
not.

There is also $PUTMSG, which is kind of like perror(3), but not quite.

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This might be a typical newbie question but I can't find any reference
to it on the net.

Working in C, how do you return the RMS$_CODE symbol for any given error
number as returned from any operation? I use strerror() to get an interpretation but it does not include said symbol.

exit(rms_return_number); will print it out so I know it must be possible.


--
House Harris Software.
Making the world a safer place for our products. https://eisner.decus.org/~brown_mi

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On 3/18/2025 9:56 AM, Arne Vajhøj wrote:

On 3/18/2025 1:58 AM, Lawrence D'Oliveiro wrote:

On Tue, 18 Mar 2025 16:24:46 +1100, Michael Brown wrote:

Working in C, how do you return the RMS$_CODE symbol for any given error >>> number as returned from any operation?

The $GETMSG system service comes to mind. I see there is a library
routine
LIB$SYS_GETMSG, not sure what that does that the system service call does
not.

Classic LIB$ SYS$ difference in API style:

                                  SYS$                LIB$
optional arguments         require placeholder   can be omitted readonly integer argument       by value          by reference string arguments            fixed length only      dynamic ok

In C it is just different:

#include <stdio.h>
#include <stdint.h>

#include <descrip.h>
#include <lib$routines.h>
#include <starlet.h>

int main(int argc, char *argv[])
{
char msg[256];
int32_t code, stat;
int16_t msglen;
$DESCRIPTOR(msgdesc, msg);
code = 98962;
stat = lib$sys_getmsg(&code, &msglen, &msgdesc);
msg[msglen] = 0;
printf("stat=%d msg=|%s|\n", stat, msg);
stat = sys$getmsg(code, &msglen, &msgdesc, 0, 0);
msg[msglen] = 0;
printf("stat=%d msg=|%s|\n", stat, msg);
return 0;
}

but in other languages the LIB$ variant can be convenient:

$ bas/obj=msgfun sys$input
program msgfun

declare integer code, msglen, stat
declare string msg
external integer function lib$sys_getmsg(integer, integer, string)

code = 98962
stat = lib$sys_getmsg(code, msglen, msg)
print stat
print "|" + msg + "|"

end program
$
$ link msgfun
$ run msgfun
1
|%RMS-E-FNF, file not found|
$ bas/obj=msgfun sys$input
program msgfun

declare integer code, msglen, stat
map (fun) string msg = 256
external integer function sys$getmsg(integer by value, integer, string,
integer by value, integer by value)

code = 98962
stat = sys$getmsg(code, msglen, msg, 0, 0)
print stat
print "|" + mid$(msg, 1, msglen) + "|"

end program
$
$ link msgfun
$ run msgfun
1
|%RMS-E-FNF, file not found|
$ bas/obj=msgfun sys$input
program msgfun

declare integer code, msglen, stat
map (fun) string msg = 256
external integer function sys$getmsg(integer by value, integer, string)

code = 98962
stat = sys$getmsg(code, msglen, msg)
print stat
!print "|" + mid$(msg, 1, msglen) + "|"

end program
$
$ link msgfun
$ run msgfun
276
$ bas/obj=msgfun sys$input
program msgfun

declare integer code, msglen, stat
declare string msg
external integer function sys$getmsg(integer by value, integer, string,
integer by value, integer by value)

code = 98962
stat = sys$getmsg(code, msglen, msg, 0, 0)
print stat
!print "|" + mid$(msg, 1, msglen) + "|"

end program
$
$ link msgfun
$ run msgfun
1537

Arne

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On 3/18/2025 1:58 AM, Lawrence D'Oliveiro wrote:

On Tue, 18 Mar 2025 16:24:46 +1100, Michael Brown wrote:

Working in C, how do you return the RMS$_CODE symbol for any given error
number as returned from any operation?

The $GETMSG system service comes to mind. I see there is a library routine LIB$SYS_GETMSG, not sure what that does that the system service call does not.

Classic LIB$ SYS$ difference in API style:

SYS$ LIB$
optional arguments require placeholder can be omitted
readonly integer argument by value by reference
string arguments fixed length only dynamic ok

Arne

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On 3/18/2025 9:56 AM, Arne Vajhøj wrote:

On 3/18/2025 1:58 AM, Lawrence D'Oliveiro wrote:

On Tue, 18 Mar 2025 16:24:46 +1100, Michael Brown wrote:

Working in C, how do you return the RMS$_CODE symbol for any given error >>> number as returned from any operation?

The $GETMSG system service comes to mind. I see there is a library
routine
LIB$SYS_GETMSG, not sure what that does that the system service call does
not.

Classic LIB$ SYS$ difference in API style:

                                  SYS$                LIB$
optional arguments         require placeholder   can be omitted readonly integer argument       by value          by reference string arguments            fixed length only      dynamic ok

Dynamic string can be made to work with system service, but it
it is a little cumbersome.

Same Basic example:

$ bas/obj=msgfun sys$input
program msgfun

declare integer code, msglen, stat
declare string msg
external integer function sys$getmsg(integer by value, integer, string,
integer by value, integer by value)

code = 98962
msg = " "
stat = sys$getmsg(code, msglen, msg, 0, 0)
msg = mid$(msg, 1, msglen)
print stat
print "|" + mid$(msg, 1, msglen) + "|"

end program
$
$ link msgfun
$ run msgfun
1
|%RMS-E-FNF, file not found|

Arne

--- SoupGate-Win32 v1.05
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On 18/3/25 16:24, Michael Brown wrote:

This might be a typical newbie question but I can't find any reference
to it on the net.

Working in C, how do you return the RMS$_CODE symbol for any given error number as returned from any operation? I use strerror() to get an interpretation but it does not include said symbol.

exit(rms_return_number); will print it out so I know it must be possible.

https://www.eight-cubed.com/examples/framework.php?file=lib_sys_getmsg.c

Cheers
Jim
--
eight-cubed.com

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This is gold!, thank you for this question fully answered. I can polish
up my error handling routines now.




On 19/3/25 01:01, Arne Vajhøj wrote:

On 3/18/2025 9:56 AM, Arne Vajhøj wrote:

On 3/18/2025 1:58 AM, Lawrence D'Oliveiro wrote:

On Tue, 18 Mar 2025 16:24:46 +1100, Michael Brown wrote:

Working in C, how do you return the RMS$_CODE symbol for any given
error
number as returned from any operation?

The $GETMSG system service comes to mind. I see there is a library
routine
LIB$SYS_GETMSG, not sure what that does that the system service call
does
not.

Classic LIB$ SYS$ difference in API style:

                                   SYS$                LIB$
optional arguments         require placeholder   can be omitted
readonly integer argument       by value          by reference
string arguments            fixed length only      dynamic ok

In C it is just different:

#include <stdio.h>
#include <stdint.h>

#include <descrip.h>
#include <lib$routines.h>
#include <starlet.h>

int main(int argc, char *argv[])
{
    char msg[256];
    int32_t code, stat;
    int16_t msglen;
    $DESCRIPTOR(msgdesc, msg);
    code = 98962;
    stat = lib$sys_getmsg(&code, &msglen, &msgdesc);
    msg[msglen] = 0;
    printf("stat=%d msg=|%s|\n", stat, msg);
    stat = sys$getmsg(code, &msglen, &msgdesc, 0, 0);
    msg[msglen] = 0;
    printf("stat=%d msg=|%s|\n", stat, msg);
    return 0;
}

--
House Harris Software.
Making the world a safer place for our products. https://eisner.decus.org/~brown_mi

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)