Shell – SH: How to make vars from one script available in the main script

bourne-shellenvironment-variablesshell

I have two scripts that need to run and both require the same variables set the same way. As a result I figured I'd break the setting of the variables out into a separate script. However, I can't seem to get this to work right where the variables are showing in the main script.

For example, this is my main script:

#!/bin/sh

. ./vars

printenv

This is what I have in the script "vars":

#!/bin/sh
MYVAR=MYVAL

echo "EXECUTED!!"

In the output, I successfully see "EXECUTED!!", but the variable MYVAR is not set to anything.

EXECUTED!!
MAIL=/var/mail/testuser
SSH_CLIENT=192.168.110.1 62953 22
USER=testuser
SHLVL=1
HOME=/home/testuser
OLDPWD=/home/testuser/test
SSH_TTY=/dev/pts/0
LOGNAME=testuser
_=./mainScript
TERM=xterm
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
LANG=en_US.UTF-8
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca=30;41:tw=30;42:ow=34;42:st=37;44:ex=01;32:*.tar=01;31:*.tgz=01;31:*.arc=01;31:*.arj=01;31:*.taz=01;31:*.lha=01;31:*.lz4=01;31:*.lzh=01;31:*.lzma=01;31:*.tlz=01;31:*.txz=01;31:*.tzo=01;31:*.t7z=01;31:*.zip=01;31:*.z=01;31:*.Z=01;31:*.dz=01;31:*.gz=01;31:*.lrz=01;31:*.lz=01;31:*.lzo=01;31:*.xz=01;31:*.bz2=01;31:*.bz=01;31:*.tbz=01;31:*.tbz2=01;31:*.tz=01;31:*.deb=01;31:*.rpm=01;31:*.jar=01;31:*.war=01;31:*.ear=01;31:*.sar=01;31:*.rar=01;31:*.alz=01;31:*.ace=01;31:*.zoo=01;31:*.cpio=01;31:*.7z=01;31:*.rz=01;31:*.cab=01;31:*.jpg=01;35:*.jpeg=01;35:*.gif=01;35:*.bmp=01;35:*.pbm=01;35:*.pgm=01;35:*.ppm=01;35:*.tga=01;35:*.xbm=01;35:*.xpm=01;35:*.tif=01;35:*.tiff=01;35:*.png=01;35:*.svg=01;35:*.svgz=01;35:*.mng=01;35:*.pcx=01;35:*.mov=01;35:*.mpg=01;35:*.mpeg=01;35:*.m2v=01;35:*.mkv=01;35:*.webm=01;35:*.ogm=01;35:*.mp4=01;35:*.m4v=01;35:*.mp4v=01;35:*.vob=01;35:*.qt=01;35:*.nuv=01;35:*.wmv=01;35:*.asf=01;35:*.rm=01;35:*.rmvb=01;35:*.flc=01;35:*.avi=01;35:*.fli=01;35:*.flv=01;35:*.gl=01;35:*.dl=01;35:*.xcf=01;35:*.xwd=01;35:*.yuv=01;35:*.cgm=01;35:*.emf=01;35:*.axv=01;35:*.anx=01;35:*.ogv=01;35:*.ogx=01;35:*.aac=00;36:*.au=00;36:*.flac=00;36:*.m4a=00;36:*.mid=00;36:*.midi=00;36:*.mka=00;36:*.mp3=00;36:*.mpc=00;36:*.ogg=00;36:*.ra=00;36:*.wav=00;36:*.axa=00;36:*.oga=00;36:*.spx=00;36:*.xspf=00;36:
SHELL=/bin/bash
PWD=/home/testuser
SSH_CONNECTION=192.168.110.1 62953 192.168.110.133 22

Best Answer

Sourcing your script only sets shell variables, while printenv shows environment variables. You will have to export the variables for printenv to show them. You may have meant to use set instead, which will show shell variables.

You could have made this script:

#!/bin/sh
export MYVAR=MYVAL

echo "EXECUTED!!"

(given that you are using bash, the export works with an assignment as shown).

By the way: when you source a file, shells do not pay any attention to the hashbang line #!/bin/sh: that is the province of the kernel in any case, except obliquely. Oddly enough, that is not mentioned in the manual page. You can see this by making two files, say "foo" and "bar":

#!/bin/bash
echo "outer $0 $SHELL"
. ./bar
printenv |fgrep MYVAR

and

#!/bin/sh
echo "inner $0 $SHELL"
export MYVAR=$MYVAL

to see that the shell variables (such as $0) are the same within the sourced file, and that the shell features are unaffected.

I add that line anyway, to help with syntax highlighting.

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