hello, everyone. I has finished a small program. When I run it in a shell, I got some information, which I hadn't expected. for example, I run my program with some invalid argument to cause it return -1, then I see the information which I use the "perror" function to print. But they are followed by other information such as ": invalid argument" or ": success". These kind of sentence never appear in my code.
Who said these? I am totally confused. Please help me.

some functions used in my code:
#include <time.h>
#include <signal.h>

timer_create(...);
timer_settime(...);

sorry for my bad English.

Ever tried to call "man 3 perror"? It is the textual description of the error in errno.

2 gentle suggestions -- if this is a C program,

• Put "C program" in the title.
• Post your Q in the Programming sub-forum.

Thanks for your kind suggestions.
As a newbie, there is really much for me to learn.

I just realized no one said anything in your 1st thread, so: Welcome to LQ !

You're welcome, thanks for listening.

BTW, you can implement both suggestions as follows:

1. I believe you can edit the title as well as the body of the post. While that won't change what has already appeared in the daily "LinuxQuestions.org Zero Reply Threads" e-mail, it should appear w/ the new title everywhere else.

2. You are allowed & encouraged to report your own post to the Mods. to ask to have it moved to a more appropriate forum.

Moved: This thread is more suitable in <Programming> and has been moved accordingly to help your thread/question get the exposure it deserves.

Did you ever get an answer?

Did you solve it on your own?

Yes, I solved it on my own, as soon as I knew it had something to
do with the perror function.

Good for you.

Could you post the details for others who might have the same problem?

Thank you for the suggestion.
Here it is:

I tried the command "man 3 perror" and got the following message:
That' the final reason.