问题
I have a script that uses passthru() to run a command. I need to set some shell environment variables before running this command, otherwise it will fail to find it's libraries.
I've tried the following:
putenv("LD_LIBRARY_PATH=/path/to/lib");
passthru($cmd);
Using putenv() doesn't appear to propagate to the command I'm running. It fails saying it can't find it libraries. When I run export LD_LIBRARY_PATH=/path/to/lib in bash, it works fine.
I also tried the following (in vain):
exec("export LD_LIBRARY_PATH=/path/to/lib");
passthru($cmd);
How can I set a shell variable from PHP, that propagates to child processes of my PHP script?
Am I limited to checking if a variable does not exist in the current environment and asking the user to manually set it?
回答1:
I'm not 100% familiar with how PHP's exec works, but have you tried: exec("LD_LIBRARY_PATH=/path/to/lib $cmd")
I know that this works in most shells but I'm not sure how PHP doing things.
EDIT: Assuming this is working, to deal with multiple variables just separate them by a space:
exec("VAR1=val1 VAR2=val2 LD_LIBRARY_PATH=/path/to/lib $cmd")
回答2:
You could just prepend your variable assignments to $cmd.
[ghoti@pc ~]$ cat doit.php
<?php
$cmd='echo "output=$FOO/$BAR"';
$cmd="FOO=bar;BAR=baz;" . $cmd;
print ">> $cmd\n";
passthru($cmd);
[ghoti@pc ~]$ php doit.php
>> FOO=bar;BAR=baz;echo "output=$FOO/$BAR"
output=bar/baz
[ghoti@pc ~]$
回答3:
A couple things come to mind. One is for $cmd to be a script that includes the environment variable setup before running the actual program.
Another thought is this: I know you can define a variable and run a program on the same line, such as:
DISPLAY=host:0.0 xclock
but I don't know if that work in the context of passthru
https://help.ubuntu.com/community/EnvironmentVariables#Bash.27s_quick_assignment_and_inheritance_trick
来源：https://stackoverflow.com/questions/9636605/export-shell-environment-variable-before-running-command-from-php-cli-script