Why does bash script variable assignment does not work?
It seemed like a good idea to write a testscript to test the commands as I encountered them but the first script does not work and altering it in other obvious ways does not fix the problem. with the error message indicating that the “+” sign is interpreted as a command not an addition operator.
Why does let not work in a shell script?
The problem is likely that /bin/sh is not the same as, or does not behave the same as, your normal shell. For example, when bash is invoked as /bin/sh, it provides a subset of its normal features. You don’t need the semi-colons at the ends of the lines. Do not use let. Use POSIX arithmetic expansion: a=$ ( ($a+1)).
Why is my bash script not working on my Mac?
If you use Sublime Text on Windows or Mac to edit your scripts: Click on View > Line Endings > Unix and save the file again. This is caused by editing file in windows and importing and executing in unix. dos2unix -k -o filename should do the trick.
Is there a bash script in / bin / bash?
#!/bin/bash # My first script echo “Hello World!” Then, when I enter ./my_script, I’m getting the error given in the title. I tried adding current directory to PATH, but that doesn’t work.. I have seen this issue when creating scripts in Windows env and then porting over to run on a Unix environment.
How to set variables in a bash script?
When you run a script, it runs in a subshell. Variables are only valid within the context of that subshell. Set them in your .bashrc or .profile and read up on variables and subshells. The export statement works down hierachy (current shell and all it’s subshells) not up as in your example.
Why is the export statement not working in Bash?
The export statement works down hierachy (current shell and all it’s subshells) not up as in your example. That causes it to run in your current shell but will not pass variables up the hierarchy either. I often want to set an environment variable without hassle.
How to assign a variable in a shell?
As always, an assignment in the shell does not accept spaces (see: Spaces in variable assignments in shell scripts ): something like var=foo bar runs the command bar with var set to foo. Or in your case, the command is +, which is just fine, since + has no special meaning to the shell (not in this context anyway).
Is it OK to declare a variable in Bash?
Bash doesn’t like spaces when you declare variables – also it is best to make every value quoted (but this isn’t as essential). The dot does the job here for you but if there was some other character there, it might be interpreted as part of the variable name.