Linked Questions
32 questions linked to/from Why is it better to use "#!/usr/bin/env NAME" instead of "#!/path/to/NAME" as my shebang?
41
votes
2
answers
49k
views
What is the difference if I start bash with "/bin/bash" or "/usr/bin/env bash"? [duplicate]
In shell scripts one specifies language interpreter on shebang(#!) line. As far as I know, it is recommended to use #!/usr/bin/env bash because env is always located in /usr/bin directory while ...
- 6,378
14
votes
2
answers
8k
views
shell script header for best compatibility [duplicate]
Which one is better:
#!/usr/bin/env sh
#!/bin/sh
empty/no header
I used to think the 1st one is the best, anyway i've found on some Linux-based systems (like Android) that pathname is missing, so ...
- 1,435
0
votes
1
answer
549
views
#!/usr/bin/env foo #!vs /usr/bin/foo [duplicate]
Which of the above forms is "better" for running bash, python etc. scripts? Why can't I just do #!$(which foo)? Is it neccecery to specify full path to env? I gather from this answer, that the path /...
- 2,643
3
votes
0
answers
779
views
#! /bin/bash or #! /usr/bin/env bash? [duplicate]
I'm trying to write some provisioning shell scripts for Vagrant dev environment. I'm used to start bash scripts as follows
#! /bin/bash
But after surfing through some git repos I found out that in ...
- 1,828
0
votes
1
answer
248
views
What's the purpose of having "env [shell]" as an interpreter? [duplicate]
I already stumbled over #!/usr/bin/env bash on numerous occasions and never questioned it. Now, I'm wondering what the purpose of wrapping the shell interpreter in an env command, i.e. why not just ...
- 2,002
53
votes
6
answers
7k
views
Is there any reason to have a shebang pointing at /bin/sh rather than /bin/bash?
In most shell scripts I've seen (besides ones I haven't written myself), I noticed that the shebang is set to #!/bin/sh. This doesn't really surprise me on older scripts, but it's there on fairly new ...
- 1,944
76
votes
3
answers
48k
views
How does /usr/bin/env know which program to use?
When I use the shebang #!/usr/bin/env python to run a script, how does the system know which python to use? if I look for a python bin path in the environment variables I find nothing.
env | grep -i ...
- 1,105
20
votes
5
answers
11k
views
How can I have more than one possibility in a script's shebang line?
I'm in a bit of an interesting situation where I have a Python script that can theoretically be run by a variety of users with a variety of environments (and PATHs) and on a variety of Linux systems. ...
- 527
26
votes
3
answers
5k
views
Why not use pathless shebangs?
Is it possible to have a shebang that, instead of specifying a path to an interpreter, it has the name of the interpreter, and lets the shell find it through $PATH?
If not, is there a reason why?
- 36.9k
12
votes
4
answers
3k
views
Distributing a script: Should I use /bin/gawk or /usr/bin/gawk for shebang?
Is gawk in /bin or /usr/bin usually? I would go with #!/usr/bin/env gawk but then I can't use arguments. Right now I'm using #!/bin/gawk -f. The script is very long and contains a lot of single ...
17
votes
5
answers
6k
views
How to start a script with clean environment?
I tried the following but it doesn't seem to work:
$ cat script.sh
#!/bin/env -i /bin/sh
/bin/env
$ script.sh
/bin/env: invalid option -- ' '
Try `/bin/env --help' for more information.
- 4,049
7
votes
3
answers
14k
views
Bash script command line argument to upper case
If I can do this in my bash shell:
$ STRING="A String"
$ echo ${STRING^^}
A STRING
How can I change my command line argument to upper case?
I tried:
GUARD=${1^^}
This line produces Bad ...
- 711
10
votes
3
answers
2k
views
Can I use a variable content as a shebang? [closed]
I have a shell script in which I want to add a shebang.
Given a variable defined as follows:
SHEBANG="#!/bin/sh"
My question is if I can use that variable in another script like this:
$SHEBANG
# ...
- 101
14
votes
1
answer
4k
views
POSIX shell scripts shebang #!/bin/sh vs #!/usr/bin/env sh, any difference?
I recently noticed that many scripts are using /usr/bin/env in their shebang. I have seen that mainly using Bash and Python, but thus far never in conjunction with POSIX sh (ash, dash,...).
I wonder ...
- 23.6k
7
votes
2
answers
5k
views
Why am I able to pass arguments to /usr/bin/env in this case?
I read in another answer that I'm not able to pass arguments to the interpreter than I'm giving to /usr/bin/env:
Another potential problem is that the #!/usr/bin/env trick doesn't let you pass ...
- 2,566