Setting environment variables in linux using bash

Question

In tcsh, I have the following simple script working:

#!/bin/tcsh
setenv X_ROOT /some/specified/path

setenv XDB    ${X_ROOT}/db
setenv PATH   ${X_ROOT}/bin:${PATH}

xrun -d xdb1 -i $1 > $2

My question is, what is the equivalent to the tcsh setenv function in bash? Is there a direct analog? The environment variables are for locating the executable.

UPDATE: Thanks everyone for your help! I'd been trying to figure this out for quite a while.

Answer 1

I think you're looking for export - though I could be wrong.. I've never played with tcsh before. Use the following syntax:

export VARIABLE=value

Answer 2

export VAR=value will set VAR to value. Enclose it in single quotes if you want spaces, like export VAR='my val'. If you want the variable to be interpolated, use double quotes, like export VAR="$MY_OTHER_VAR".

Answer 3

VAR=value sets VAR to value.

After that export VAR will give it to child processes too.

export VAR=value is a shorthand doing both.

Answer 4

The reason people often suggest writing

VAR=value
export VAR

instead of the shorter

export VAR=value

is that the longer form works in more different shells than the short form. If you know you're dealing with bash, either works fine, of course.