<div dir="ltr"><div>I use #!/bin/bash explicitly because I tend to use bash-isms in my scripts and I'd rather not have it fail part way because I'm using a strictly POSIX interpreter on accident. I'd prefer it to not run at all if bash isn't present. If you are diligent about using only POSIX features, then yes, using #!/bin/sh is a better choice.<br>
<br></div>QH<br></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, Jun 25, 2013 at 9:04 AM, Stephen Queen <span dir="ltr"><<a href="mailto:svqueen@gmail.com" target="_blank">svqueen@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div><div><div><div><div><div><div>When sourcing a file #!/bin/bash has no effect. It looks to me as if it is seen as a comment. For fun try this:<br>
</div><div>cat my_fun<br></div>#!/bin/foo<br>
</div>export BAR=Hello<br><br></div>Now source it<br></div>. my_fun<br></div>No error messages. Now <br></div>$ echo $BAR<br></div>Hello<br><br></div>So you can add #!/bin/bash, to a file you are going to source, but it has no effect.<br>
</div>Though if you are always going to add the interpreter to the first line #!/bin/sh is a better choice. It is more portable. It is usually a link to a default shell, whereas bash is not necessarily installed on all systems. A lot of embedded systems don't use bash. <br>
<br><br></div><div>A good example of a sourced file on a debian system would be /lib/init/vars.sh. It is sourced by a good number of the start up scripts.<br><br></div><div>Steve<br></div></div><div class="HOEnZb"><div class="h5">
<div class="gmail_extra"><br>
<br><div class="gmail_quote">On Mon, Jun 24, 2013 at 5:03 PM, Quentin Hartman <span dir="ltr"><<a href="mailto:qhartman@gmail.com" target="_blank">qhartman@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr"><div><div>Just a note that removing the #! statement at the top of the file is usually a bad idea. That doesn't directly start a new shell, that tells the system (not sure if it's bash itself, or if it's a kernel thing) which interpreter to use for the script. You can get weird results if you leave that out and make the script executable.<br>
<br></div>It does though create a new subshell as was mentioned, which always happens with script execution (having nothing to do with #!), which is why those env_vars don't show up in the parent shell. In order to get them to show up in the parent shell, you have to source them from the parent shell:<br>
<br>04:57 PM:qhartman@qhstation$ cat foo.sh<br>#!/bin/bash<br>export FOO=bar<br><br>CWD:~<br>04:57 PM:qhartman@qhstation$ ./foo.sh <br><br>CWD:~<br>04:57 PM:qhartman@qhstation$ echo $FOO<br><br><br>CWD:~<br>04:57 PM:qhartman@qhstation$ source foo.sh<br>
<br>CWD:~<br>04:58 PM:qhartman@qhstation$ echo $FOO<br>bar<br><br><br></div>If you need to have those vars set outside of the context of the script you are running, you need to add or modify those vars in the appropriate user's login shell config (usually .bashrc), and then the next time that user invokes a shell they will be set how you want.<br>
</div><div><div><div class="gmail_extra"><br><br><div class="gmail_quote">On Mon, Jun 24, 2013 at 3:28 PM, Mark G. Harvey <span dir="ltr"><<a href="mailto:markgharvey@yahoo.com" target="_blank">markgharvey@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div style="font-size:10pt;font-family:Courier New,courier,monaco,monospace,sans-serif"><div><span style="font-size:13px"><br>
</span></div><div style="font-style:normal;background-color:transparent"><span style="font-size:small"><br></span></div><div style="font-style:normal;background-color:transparent"><span style="font-size:13px">so removing #!/bin/bash/ at the top of the script to stay within the same shell session doesn't make any detectable difference</span></div>
<div style="font-style:normal;background-color:transparent"><span style="font-size:13px"><br></span></div><div style="font-style:normal;background-color:transparent"><span style="font-size:13px"><span>I also added sourcing the file where the variables are set ( # </span><span>source </span><span>/etc/profile.d/00_jdk.sh
) </span><span style="background-color:transparent"> </span></span></div><div style="font-style:normal;background-color:transparent"><span style="background-color:transparent;font-size:13px"><br></span></div><div style="font-style:normal;background-color:transparent">
<span style="background-color:transparent;font-size:13px">the variables PATH and JAVA_HOME show up correct when the script is running ... but when finished, the variables are still not changed</span></div><div style="font-style:normal;background-color:transparent">
<span style="background-color:transparent;font-size:13px"><br></span></div><div style="background-color:transparent"><span style="font-size:13px"><div><div style="background-color:transparent">[root@87148-mondev01 ~]# echo $PATH</div>
</div><div style="background-color:transparent">/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin ... should be appended with <span style="background-color:transparent">/usr/java/jdk1.7.0_21/bin</span></div>
<div><div style="background-color:transparent">[root@87148-mondev01 ~]# echo $JAVA_HOME</div></div><div style="font-style:normal;background-color:transparent">... should have an entry <span style="background-color:transparent">/usr/java/jdk1.7.0_21/bin ... but it is blank </span></div>
</span></div><div style="font-style:normal;background-color:transparent"><span style="font-size:13px"><br></span></div><div style="font-style:normal;background-color:transparent"><span style="font-size:13px"><br></span></div>
<div style="font-style:normal;background-color:transparent"><span style="font-size:small"><br></span></div><div><br><blockquote style="border-left:2px solid rgb(16,16,255);margin-left:5px;margin-top:5px;padding-left:5px">
<div style="font-family:'Courier New',courier,monaco,monospace,sans-serif;font-size:10pt"> <div style="font-family:'times new roman','new york',times,serif;font-size:12pt"> <div dir="ltr"> <hr size="1">
<font face="Arial"> <b><span style="font-weight:bold">From:</span></b> "<a href="mailto:dennisjperkins@comcast.net" target="_blank">dennisjperkins@comcast.net</a>" <<a href="mailto:dennisjperkins@comcast.net" target="_blank">dennisjperkins@comcast.net</a>><br>
<b><span style="font-weight:bold">To:</span></b> CLUE's mailing list <<a href="mailto:clue@cluedenver.org" target="_blank">clue@cluedenver.org</a>> <br> <b><span style="font-weight:bold">Sent:</span></b> Monday, June 24, 2013 2:56 PM<div>
<div><br> <b><span style="font-weight:bold">Subject:</span></b> Re: [clue] env variables<br> </div></div></font> </div><div><div> <div><br><div><div><div style="font-size:12pt;font-family:Arial">The proper place for these might be in one of the Bash config files.<br>
<br><hr><b>From: </b>"Stephen Queen" <<a href="mailto:svqueen@gmail.com" target="_blank">svqueen@gmail.com</a>><br><b>To: </b>"Mark G. Harvey" <<a href="mailto:markgharvey@yahoo.com" target="_blank">markgharvey@yahoo.com</a>>, "CLUE's mailing list" <<a href="mailto:clue@cluedenver.org" target="_blank">clue@cluedenver.org</a>><br>
<b>Sent: </b>Monday, June 24, 2013 2:37:49 PM<br><b>Subject: </b>Re: [clue] env variables<br><br><div dir="ltr"><div><div><div><div><div><div>When you add <br>#!/bin/bash<br></div>to the top of your script, you are starting a new shell. When the script completes, it exits that shell. Instead "source" you environmental variables. Create a file my_env that contains your export commands<br>
# cat my_env<br>export JAVA_HOME=/usr/java/jdk1.7.0_21<br>export PATH=$PATH:/usr/java/jdk1.7.0_21/bin<br><br></div>Then source the file <br></div>. my_env<br></div><div>(space between . and my_env, does not need to be executable).<br>
</div>Now when you<br></div># echo $JAVA_HOME<br>usr/java/jdk1.7.0_21<br># <br><br></div>Steve<br><div><br><div><div><div><div> <br></div></div></div></div></div></div><div><br><br><div>
On Mon, Jun 24, 2013 at 1:54 PM, Mark G. Harvey <span dir="ltr"><<a rel="nofollow" href="mailto:markgharvey@yahoo.com" target="_blank">markgharvey@yahoo.com</a>></span> wrote:<br><blockquote style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div style="font-size:10pt;font-family:'Courier New',courier,monaco,monospace,sans-serif"><div>CLUE experts, </div><div><br>This puzzle is likely simple for you folks, but it has me stumped. I've done considerable digging but have found mixed advice. <br>
<br>I've created a script to download from a local repo via wget an rpm to install JDK ... no problem there. <br><br>Here's the part I can't get right ... setting the variables so I can run scripts to install Tomcat ... Any attempt will bomb if it can't find /usr/java/jdk1.7.0_21/bin <br>
<br><br># set JAVA_HOME variable ... tried in vain<br>echo "setting JAVA_HOME variable variable for the session" <br>JAVA_HOME=/usr/java/jdk1.7.0_21<br># export JAVA_HOME variable ... tried in vain<br>echo "exporting JAVA_HOME variable variable for the session" <br>
export JAVA_HOME=/usr/java/jdk1.7.0_21<br>echo
"JAVA_HOME variable: $JAVA_HOME"<br><br># set PATH variable for the session ... tried in vain<br>echo "setting PATH variable for the session" <br>PATH=$PATH:/usr/java/jdk1.7.0_21/bin<br># export PATH variable for the session<br>
echo "exporting PATH variable for the subsequent sessions & processes" <br>export PATH=$PATH:/usr/java/jdk1.7.0_21/bin<br>echo "show PATH variable: $PATH"<br><br>sleep 3 # wait<br><br># create script to set JAVA_HOME & PATH variables in /etc/profile.d/00_jdk.sh script for all accounts<br>
# use echo command with single quotes to write the literal statement to the script<br>touch /etc/profile.d/00_jdk.sh<br>echo '#!/bin/bash' >> /etc/profile.d/00_jdk.sh<br>echo '# set JAVA_HOME in /etc/profile.d/00_jdk.sh script for all accounts' >> /etc/profile.d/00_jdk.sh<br>
echo 'JAVA_HOME=/usr/java/jdk1.7.0_21' >> /etc/profile.d/00_jdk.sh<br>echo '# set PATH in /etc/profile.d/00_jdk.sh
script for all accounts' >> /etc/profile.d/00_jdk.sh<br>echo 'PATH=$PATH:/usr/java/jdk1.7.0_21/bin' >> /etc/profile.d/00_jdk.sh <br><br>sleep 3 # wait<br><br>echo "review contents of /etc/profile.d/00_jdk.sh"<br>
cat /etc/profile.d/00_jdk.sh<br><br><br>... results of install ... added some blank lines for readability ...<br><br>[root@87148-mondev01 ~]# ./<a rel="nofollow" href="http://dev_install_jdk1.7-1.0.0.sh/" target="_blank">DEV_install_jdk1.7-1.0.0.sh</a> <br>
installation: Oracle/Sun jdk 1.7 64-bit<br>remount /tmp with execute privledge<br>changed to /tmp<br>Pulling package from Artifactory Repo Management Server<br>--2013-06-24 13:24:38-- <a rel="nofollow">https://<RepoHost>/artifactory/simple/ext-release-local/oracle/jdk/7u21-linux/jdk-7u21-linux-x64.rpm</a><br>
Resolving <RepoHost>... 10.33.44.10<br>Connecting to <RepoHost>|10.33.44.10|:443...
connected.<br><br>HTTP request sent, awaiting response... 200 OK<br><br>Length: 85388149 (81M) [application/x-rpm]<br>Saving to: “jdk-7u21-linux-x64.rpm”<br><br>100%[=======================================================================================================================================>] 85,388,149 52.7M/s in 1.5s <br>
<br>2013-06-24 13:24:40 (52.7 MB/s) - “jdk-7u21-linux-x64.rpm” saved [85388149/85388149]<br><br>jdk downloaded<br>check /tmp/ contents for jdk<br>-rw-r--r--. 1 root root 85388149 Jun 6 16:46 jdk-7u21-linux-x64.rpm<br>install jdk rpm<br>
Preparing... ########################################### [100%]<br>package jdk-2000:1.7.0_21-fcs.x86_64 is already installed ........ due to subsequent running of this script<br>install jdk complete<br>
<br>setting JAVA_HOME variable variable for the session<br>exporting
JAVA_HOME variable variable for the session<br><br>... when tested in the script, the correct answer shows up ... <br><br>JAVA_HOME variable: /usr/java/jdk1.7.0_21 <br><br>setting PATH variable for the session<br>exporting PATH variable for the subsequent sessions & processes<br>
<br>... when tested in the script, the correct answer shows up ... <br><br><br>show PATH variable: /usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin:/usr/java/jdk1.7.0_21/bin:/usr/java/jdk1.7.0_21/bin<br>
<br>review contents of /etc/profile.d/00_jdk.sh<br>#!/bin/bash<br># set JAVA_HOME in /etc/profile.d/00_jdk.sh script for all accounts<br>JAVA_HOME=/usr/java/jdk1.7.0_21<br># set PATH in /etc/profile.d/00_jdk.sh script for all accounts<br>
PATH=$PATH:/usr/java/jdk1.7.0_21/bin<br>remount /tmp removing execute privledge<br>finished<br><br><br>... after script runs, when tested from CLI, variables not not correct
... <br><br>[root@87148-mondev01 ~]# echo $JAVA_HOME<br><br>[root@87148-mondev01 ~]# echo $PATH<br>/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin<br><br><br><br>[root@87148-mondev01 ~]# exit<br>logout<br>
<br>[vwadmin@87148-mondev01 ~]$ su -<br>Password: <br><br><br>... now the variable additions show up ... they come from the /etc/profile.d/00_jdk.sh script created as part of the JDK download & install ... <br><br>[root@87148-mondev01 ~]# echo $PATH<br>
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/java/jdk1.7.0_21/bin:/root/bin<br><br>[root@87148-mondev01 ~]# echo $JAVA_HOME<br>/usr/java/jdk1.7.0_21<br><br><br><br>... How can I get the variables to be available for the current root session & usable for subsequent installations? Trying to avoid the logout / login ... <br>
<br><br><br>Thanks for your help. <br></div></div></div><br>_______________________________________________<br>
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