exec command doesn't strip trailing spaces

[TheLQ]

Reproducible for a while, but just tested on freshly built master of WLC and sway

The default firefox.desktop file contains this entry

Exec=firefox %u

When running from dmenu the following command gets sent

i3-msg 'exec "firefox "'

Under i3 this opens firefox. Under sway -v -d this is in the log

Handling command 'exec "firefox "'
find_handler(exec) 0
Executing "firefox "
Child process created with pid 4934
{ "success": true }
IPC Client -1 disconnected
/bin/sh: 1: firefox : not found

Presumably its failing because it's trying to run a binary called firefox instead of firefox. I can't imagine a process where ending or starting spaces not inside quotes are relevant. Even bash strips out spaces

[ddevault]

Related to #519?

[TheLQ]

It's been happening for a long time, I've only now made an issue for it. The top of the log says

Starting sway version 378a45c (2016-03-18, branch "master")

which is that merge commit

[ddevault]

Got it. I'm pretty sure exec just runs the command with sh, but worth double checking.

[mikkeloscar]

exec will run it as /bin/sh -c '"firefox "'.

I would argue that it's wrong to run i3-msg 'exec "firefox "' if you don't intend to run the command "firefox ". How should exec know it isn't meant as a single argument when passed as a single argument?

Unless this should be a valid way to use exec: exec "/bin/prog -a -b -c", but I think that will just be confusing.

[ddevault]

I'm inclinded to agree with @mikkeloscar on this one.

[ddevault]

Closing as intended behavior.

[TheLQ]

The problem is on Ubuntu 15.10 using the default i3-dmenu-desktop I cannot open firefox, gedit, libreoffice, or any app that takes an optional parameter. The only way I've been able to run most apps is by opening a terminal and running the command from there which is very frustrating

Sway's handling of exec is incompatible with i3 and scripts that run i3-msg 'exec "someCommand $optionalArgs"'. It handles arguments completely differently as the above example with an argument like -v will try to run a binary called someCommand -v as you see below with libreoffice writer.

While I agree the usage of quoting is questionable, the fact that i3's exec command, i3-dmenu-desktop (and maybe other launchers), and peoples configs, scripts, and apps assume that i3-msg 'exec "firefox http://google.com"'' means run a binary called firefox with the argument http://google.com and not a binary called firefox http://google.com should mean that sway does the same to remain compatible.

Here's the logs of trying to run those apps. I tested all of the commands with the same quoting under i3 and they worked fine

Event on IPC listening socket
Handling command 'exec  "libreoffice --writer "'
find_handler(exec) 0
Executing "libreoffice --writer "
Child process created with pid 29722
{ "success": true }
IPC Client -1 disconnected
/bin/sh: 1: libreoffice --writer : not found

Event on IPC listening socket
Handling command 'exec  "gedit "'
find_handler(exec) 0
Executing "gedit "
Child process created with pid 29892
IPC Client -1 disconnected
{ "success": true }
/bin/sh: 1: gedit : not found

Event on IPC listening socket
Handling command 'exec  "steam steam://rungameid/49520"'
find_handler(exec) 0
Executing "steam steam://rungameid/49520"
Child process created with pid 29906
{ "success": true }
IPC Client -1 disconnected
/bin/sh: 1: steam steam://rungameid/49520: not found

Event on IPC listening socket
Handling command 'exec  "shotwell "'
find_handler(exec) 0
Executing "shotwell "
Child process created with pid 29915
{ "success": true }
IPC Client -1 disconnected
/bin/sh: 1: shotwell : not found

[ddevault]

Well, if it's not the behavior of i3, I'll concede. I'd consider that a failing of i3, for what it's worth.

[mikkeloscar]

I see this as an opportunity to correct a poor design choice. It seems to be a single line patch to fix the behavior of i3-dmenu-desktop and I doubt that many people have custom scripts with this weird exec format (but you never know).

I'll make a PR for i3-dmenu-desktop and see what they say about it.

[ddevault]

I'll make a PR for i3-dmenu-desktop and see what they say about it.

If it gets merged, we're golden, but I'm not going to break backwards compatability with i3 over this if necessary.

[mikkeloscar]

It turns out that the way i3 handles exec arguments is more crazy than I thought so my PR won't work because it breaks some edge cases in i3.
For instance you can't use a shell command with , even if you quote it, because i3 thinks it chaining i3 commands. The whole command must be quoted in that case (i.e. exec "firefox http://example.com/bad,url" instead of exec firefox "http://example.com/bad,url").