This question already has answers here:
Why do you need to put #!/bin/bash at the beginning of a script file?
(10 answers)
What is the preferred Bash shebang ("#!")?
(6 answers)
Closed 4 years ago.
What is the significant of using #!/bin/bash in the starting of bash script? Can we write a bash script without #!/bin/bash ?
This line is called shebang. It’s a ‚magic‘ line telling the program loader (kernel) how to execute a script on unixoid systems.
Cf. https://en.m.wikipedia.org/wiki/Shebang_(Unix)
Related
This question already has answers here:
How do I parse command line arguments in Bash?
(40 answers)
How to get exact command line string from shell?
(2 answers)
Closed 3 years ago.
Suppose my script.sh could take a number of options and arguments. What is the best way to find out what the script was invoked with (form inside the script)?
For eg., someone called it with script.sh --foo_option bar_arg
Is there a way to echo that exact command they typed from inside the script?
I've tried echo !! which does not work inside a script.
This question already has answers here:
How to read a file into a variable in shell?
(9 answers)
Difference between sh and Bash
(11 answers)
Closed 4 years ago.
I have store ip address with port in a file and I want to read it using shell script. Thus file serverIP has data 192.168.1.17:3000. I am using following bash script to read it
IPAddressFile=/home/geo/serverIP
SERVER_IP_PORT=$(<$IPAddressFile)
echo $SERVER_IP_PORT
But this script echo empty string. Where I am making mistake?
If you're going to use bash-only syntax like $(<...), your script must be run with bash, not sh.
Thus, either run bash yourscript or add a #!/bin/bash (or similar) shebang, flag the file executable, and invoke it as a command, for example ./yourscript
As an alternative that's both efficient and compatible with POSIX sh:
IFS= read -r SERVER_IP_PORT <"$IPAddressFile"
This question already has answers here:
How to run a process with a timeout in Bash? [duplicate]
(2 answers)
How do I pause my shell script for a second before continuing?
(10 answers)
Closed 5 years ago.
I am new to shell scripting, and would like to know how to call the second script 5 seconds after running the first script. In the example below, I would like ./csv3xlsx_osx to run 5 seconds after the python script completes.
python script.py
./csv2xlsx_osx -infile input.csv -outfile ouptut.xlsx
How would one go about doing the equivalent of Javascript's setTimeout() in shell?
This question already has answers here:
Writing a Bash script without the shebang line
(2 answers)
Bash script execution with and without shebang in Linux and BSD
(2 answers)
Closed 5 years ago.
If after logging into my system I type: bash (to use bash subshell) and then try to run a bash script (e.g. example.sh), then does it matter if I do not put #!/bin/bash as the first line of the script or it is fine since I am already inside bash subshell?
This question already has answers here:
How does the #! shebang work?
(3 answers)
Closed 5 years ago.
while following this tutorial I found a command
#!/bin/sh
git --work-tree=/var/www/domain.com --git-dir=/var/repo/site.git checkout -f
I don't understand the meaning of #!/bin/sh. I tried to search it but google removes the ! symbol from search results.
What does #!/bin/sh mean here?
Please help.
#! specifies the program with which the script should be executed if you not explicitly call it which any
in your case, if you call your script with: <scriptname.sh> Linux will execute it as /bin/sh <scriptname.sh>