| Title: | Alpha Developer Support |
| Notice: | [email protected], 800-332-4786 |
| Moderator: | HYDRA::SYSTEM |
| Created: | Mon Jun 06 1994 |
| Last Modified: | Fri Jun 06 1997 |
| Last Successful Update: | Fri Jun 06 1997 |
| Number of topics: | 3722 |
| Total number of notes: | 11359 |
Company Name : The Jet Propulsion Laboratory
Contact Name : Al Wong
Phone : (818) 795-4928, x234
Fax :
Email : [email protected]
Date/Time in : 23-MAY-1997 07:42:02
Entered by : John Talatinian
SPE center : MRO
Category : UNIX
OS Version :
System H/W : ALPHA
Brief Description of Problem:
-----------------------------
Hello,
I'm getting an error code from the system() function (C language)
which doesn't appear to be documented anywhere. I am invoking
system() which runs a shell script which in turn runs FTP.
However the FTP invocation is failing although system() exits
normally.
The return status from system() is 256!? What does this code mean?
Note errno is NOT set. errno is still zero. 256 is the int value
that is returned by system().
According to the man page, system() will return 0 if successful.
On error system() will return -1 and errno is set. Any other value
(such as 256!) is the same as wait(). Looking at the wait() man page,
it tells you to see the wait.h file. Looking at the wait.h file,
there is no mention of the 256 return status! What gives?
Looking at the other header files, there is no clue about the
return values of system(). Tried looking at the DEC website and
could not find a list of values. Actually, a list of the possible
values system() returns and their meanings would be very helpful.
I'm working on a DEC Alpha with OSF/1 and the cc compiler that
came with the machine.
I would appreciate a timely answer. Thank you.
-----------------------------------------------------------
Al Wong, [email protected]
The Jet Propulsion Laboratory
Pasadena, California
(818) 795-4928, x234
-----------------------------------------------------------
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 3657.1 | HYDRA::MGREENFIELD | Fri May 23 1997 15:21 | 52 | ||
other related notes mike From: HYDRA::MGREENFIELD 23-MAY-1997 14:16:25.82 To: crl::"[email protected]",me CC: Subj: response Al; By way of introduction, I am Mike Greenfield and am working on your Digital Unix issue. I went down the same path as you (looked at wait.h and even the dunix sources), but did not see any obvious list of status return codes. I have escalated this request to DUNIX Engineering for help - just wanted to ack that we got the note and are working on it. Can you send me what version of dunix you are using, what your compiler/link switches are and if possible, the shell script you are calling? Thanks Mike SPE Alpha Support From: HYDRA::MGREENFIELD 23-MAY-1997 14:09:53.55 To: smurf::booth,me CC: Subj: isv help request Sarah; I am having trouble answering the attached isv's question and would be grateful if your team could provide some guidance. Is there a reference that provides all of the exit status codes for system(). Looking at sys/wait.h was not illuminating. If further information is needed from the ISV, please let me know what should be requested. Thanks regards, Mike | |||||
| 3657.2 | HYDRA::MGREENFIELD | Fri May 23 1997 17:33 | 31 | ||
spoke with al and got additional details 1) his email signature file is wrong. Correct address is [email protected] 2) situation is a bit more complex than his note let on: his simple c program is a cgi that is run in the context of the netscape server. he has defined environment variable for home, shell and path he has defined a .netrc to automate the process his script is as simple as !/bin csh ftp -i machine-name his script works when not run as a cgi script he gets a 256 every time he runs this as the cgi (so it does not appear that this is the child process pid as suggested in the man 2 wait pages. man system suggests that the call does not return until the shell script completes and the child exits. Al agreed to send me his code and netrc fragments Mike | |||||