Print condition result directly in bash without using if
Let's say I have this simple code:
echo "Are there any arguments?"
if [ $# -eq 0 ]; then
echo "false"
else
echo "true"
fi
As you can see it would be better to just have opportunity to directly print condition result, but I don't know how to do it.
It would be something like:
echo "$([ $# -eq 0 ])"
But it doesn't work that way. Can we do this without if?
bash shell test
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
add a comment |
Let's say I have this simple code:
echo "Are there any arguments?"
if [ $# -eq 0 ]; then
echo "false"
else
echo "true"
fi
As you can see it would be better to just have opportunity to directly print condition result, but I don't know how to do it.
It would be something like:
echo "$([ $# -eq 0 ])"
But it doesn't work that way. Can we do this without if?
bash shell test
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
You can try zsh. Zsh will change PS1 color (command prompt color) according to$?(the return value of the last command). imgur.com/a/yBz2H
– Weekend
Aug 10 '17 at 16:04
add a comment |
Let's say I have this simple code:
echo "Are there any arguments?"
if [ $# -eq 0 ]; then
echo "false"
else
echo "true"
fi
As you can see it would be better to just have opportunity to directly print condition result, but I don't know how to do it.
It would be something like:
echo "$([ $# -eq 0 ])"
But it doesn't work that way. Can we do this without if?
bash shell test
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
Let's say I have this simple code:
echo "Are there any arguments?"
if [ $# -eq 0 ]; then
echo "false"
else
echo "true"
fi
As you can see it would be better to just have opportunity to directly print condition result, but I don't know how to do it.
It would be something like:
echo "$([ $# -eq 0 ])"
But it doesn't work that way. Can we do this without if?
bash shell test
bash shell test
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
edited Oct 15 '15 at 22:50
Gilles
538k12810891606
538k12810891606
asked Oct 15 '15 at 19:34
ctomekctomek
12015
asked Oct 15 '15 at 19:34
ctomekctomek
12015
asked Oct 15 '15 at 19:34
ctomekctomek
12015
12015
You can try zsh. Zsh will change PS1 color (command prompt color) according to$?(the return value of the last command). imgur.com/a/yBz2H
– Weekend
Aug 10 '17 at 16:04
add a comment |
You can try zsh. Zsh will change PS1 color (command prompt color) according to$?(the return value of the last command). imgur.com/a/yBz2H
– Weekend
Aug 10 '17 at 16:04
You can try zsh. Zsh will change PS1 color (command prompt color) according to
$?(the return value of the last command). imgur.com/a/yBz2H– Weekend
Aug 10 '17 at 16:04
You can try zsh. Zsh will change PS1 color (command prompt color) according to
$?(the return value of the last command). imgur.com/a/yBz2H– Weekend
Aug 10 '17 at 16:04
add a comment |
3 Answers
3
active
oldest
votes
You can use the list control operators && and || instead:
[[ $# -eq 0 ]] && { echo false; } || { echo true; }
The { } group a list of commands, you don't need them for just a single command, but they often make such constructions more readable.
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
add a comment |
You can use $? that keeps the exit code of the last executed command:
echo "Are there any arguments?"
[ $# -eq 0 ]
echo $?
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
add a comment |
Since I can't post comments yet (insufficient rep), I'll point out in a new answer that mr-spuratic's solution also works with single brackets, like so:
[ $# -eq 0 ] && { echo false; } || { echo true; }
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
add a comment |
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3 Answers
3
active
oldest
votes
3 Answers
3
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can use the list control operators && and || instead:
[[ $# -eq 0 ]] && { echo false; } || { echo true; }
The { } group a list of commands, you don't need them for just a single command, but they often make such constructions more readable.
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
add a comment |
You can use the list control operators && and || instead:
[[ $# -eq 0 ]] && { echo false; } || { echo true; }
The { } group a list of commands, you don't need them for just a single command, but they often make such constructions more readable.
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
add a comment |
You can use the list control operators && and || instead:
[[ $# -eq 0 ]] && { echo false; } || { echo true; }
The { } group a list of commands, you don't need them for just a single command, but they often make such constructions more readable.
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
You can use the list control operators && and || instead:
[[ $# -eq 0 ]] && { echo false; } || { echo true; }
The { } group a list of commands, you don't need them for just a single command, but they often make such constructions more readable.
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
answered Oct 15 '15 at 19:46
mr.spuraticmr.spuratic
6,9811128
6,9811128
add a comment |
add a comment |
You can use $? that keeps the exit code of the last executed command:
echo "Are there any arguments?"
[ $# -eq 0 ]
echo $?
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
add a comment |
You can use $? that keeps the exit code of the last executed command:
echo "Are there any arguments?"
[ $# -eq 0 ]
echo $?
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
add a comment |
You can use $? that keeps the exit code of the last executed command:
echo "Are there any arguments?"
[ $# -eq 0 ]
echo $?
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
You can use $? that keeps the exit code of the last executed command:
echo "Are there any arguments?"
[ $# -eq 0 ]
echo $?
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
answered Oct 15 '15 at 19:46
chorobachoroba
26.7k44975
26.7k44975
add a comment |
add a comment |
Since I can't post comments yet (insufficient rep), I'll point out in a new answer that mr-spuratic's solution also works with single brackets, like so:
[ $# -eq 0 ] && { echo false; } || { echo true; }
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
add a comment |
Since I can't post comments yet (insufficient rep), I'll point out in a new answer that mr-spuratic's solution also works with single brackets, like so:
[ $# -eq 0 ] && { echo false; } || { echo true; }
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
add a comment |
Since I can't post comments yet (insufficient rep), I'll point out in a new answer that mr-spuratic's solution also works with single brackets, like so:
[ $# -eq 0 ] && { echo false; } || { echo true; }
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
Since I can't post comments yet (insufficient rep), I'll point out in a new answer that mr-spuratic's solution also works with single brackets, like so:
[ $# -eq 0 ] && { echo false; } || { echo true; }
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
answered 4 mins ago
MrPotatoHeadMrPotatoHead
11
11
add a comment |
add a comment |
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You can try zsh. Zsh will change PS1 color (command prompt color) according to
$?(the return value of the last command). imgur.com/a/yBz2H– Weekend
Aug 10 '17 at 16:04