FEEDBACK

[unique olive]

Hi everyone, i have just coded a shell with the following goal:

In Unix-like system shells, you can hang the & character at the end of a command line to indicate that the command should be run in the background: i.e., the shell should not crash pending the termination of the command, but must continue parallel to the command and display the next prompt immediately. Implemented in dsh the execution of a command in the background through the character &.

I would love to receive feedbacks from you guys. I have no experience on this kind of things so if my program has any type of error or bug, please lemme know it.
Thank you guys!

[green terrace]

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[dense mango]

couple minor things (in order of appearance):

char _path[...] = ...;```
is global which is frowned upon since it has no reason of being such (it starting with an underscore might be UB as well. can quite remember)

```c
    do{
        cur++;
        if(buf[cur] == '\n'){
            buf[cur] = '\0';
            break;
        }
    }while(buf[cur] != '\0');```
although fine can be either replaced with `strchr` or just `buf[strcspn(buf, "\n")] = 0;`

and last - your `do_exec` has the potential of creating zombies processes (i.e. the `exec` process finished but its entry is still occupied). it might be better here to store all `pid`s within a vector like structure and `wait` on them at some point (either before your shell terminates or some other time)

[pliant onyx]

to avoid the zombie process issue, its best to set a handler for SIGCHLD

that triggers when a child exits

also, it would be best to use $PATH instead of hardcoding it

[dense mango]

that would be a better approach, though one need to call sigaction with SA_NOCLDSTOP

[unique olive]

Thank u guys!
Later i am gonna fix these things

[green terrace]

@unique olive Has your question been resolved? If so, type !solved :)

[plain wasp]

There's also at least one potential uninitialized read

[unique olive]

What do u mean?

[plain wasp]

In do_exec() if arg_list[0] is NULL

[green terrace]

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[unique olive]

it was checked into the main function, wasn't it?

[plain wasp]

I think so, yes, so it's probably just a technicality in this case. But it's brittle design and will break easily.

[unique olive]

Yeah

Obv, this is my first shell, i am learning about it