Timeline for Setting an environment variable before a command in Bash is not working for the second command in a pipe
Current License: CC BY-SA 3.0
17 events
| when toggle format | what | by | license | comment | |
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| Jul 16 at 19:30 | comment | added | majorgear | @DennisWilliamson That worked great. Ty. | |
| Jul 14 at 22:51 | comment | added | Dennis Williamson |
@majorgear: Space separated: FOO=bar baz=qux myvar=someval bash -c 'somecommand someargs | somecommand2'
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| Jul 14 at 2:50 | comment | added | majorgear | how do you set more than one? Say 2 environment variables? are they space separated, comma separated, or other? | |
| Apr 25, 2019 at 18:50 | comment | added | mwag | @DennisWilliamson, thanks for noticing that and asking in the other forum. When I run on 3.2.57(1)-release (x86_64-apple-darwin17) I get a blank, and when I run on 3.2.57(1)-release (x86_64-apple-darwin14) I get the warning + variable. | |
| Apr 25, 2019 at 13:05 | comment | added | Dennis Williamson | I have asked a question about this on apple.stackexchange.com. | |
| Apr 25, 2019 at 12:53 | comment | added | Dennis Williamson |
@mwag: I wasn't invoking dyld either. It seems to automagically get invoked. What version of MacOS are you running and what does bash --version say? I just checked and the result that I reported above is because I was using Bash 5. When I use /bin/bash (Bash 3.2), I get no warning and a blank line is echoed (as if the variable were empty). The dynamic loader is doing something behind the scenes regardless.
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| Apr 25, 2019 at 2:54 | comment | added | mwag |
@DennisWilliamson: I am not invoking dyld, I am invoking echo, and on my system, it does fail: running the exact, verbatim command DYLD_X=foox bash -c 'echo $DYLD_X', nothing at all gets echo'd (but it does if I use eval instead of bash -c)
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| Apr 25, 2019 at 2:24 | comment | added | Dennis Williamson |
@mwag: I don't know anything about dyld ("the dynamic linker"), but it evidently watches for variables that start with DYLD_ and it recognizes a certain set of them but complains about ones it doesn't know about. The "fails" you refer to is specifically a warning message output by dyld: "dyld: warning, unknown environment variable: DYLD_X". Note that that is a warning, not an error, and the value of the variable is actually output.
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| Apr 24, 2019 at 22:49 | comment | added | mwag |
Odd: on OSX, FOO_X=foox bash -c 'echo $FOO_X' works as expected but with specific var names it fails: DYLD_X=foox bash -c 'echo $DYLD_X' echos blank. both work using eval instead of bash -c
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| Mar 25, 2016 at 20:12 | history | rollback | Dennis Williamson |
Rollback to Revision 1
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| Mar 25, 2016 at 17:22 | history | edited | Roman Pushkin | CC BY-SA 3.0 |
Add example with accessing a variable.
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| Jan 22, 2016 at 19:07 | comment | added | Pushpendre | Note that if your command already has two levels of quotes then this method becomes extremely unsatisfactory because of quote hell. In that situation exporting in subshell is much better. | |
| Mar 24, 2015 at 20:17 | comment | added | ThorSummoner |
Note that if you need to run your somecommand as sudo, you need to pass sudo the -E flag to pass though variables. Because variables can introduce vulnerabilities. stackoverflow.com/a/8633575/1695680
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| Jun 1, 2012 at 19:49 | vote | accept | MartyMacGyver | ||
| Jun 1, 2012 at 19:45 | comment | added | Dennis Williamson | @MartyMacGyver: None that I can think of. It won't work with curly braces either. | |
| Jun 1, 2012 at 19:44 | comment | added | MartyMacGyver | This satisfies my criteria (one-liner without needing "export")... I take it there's no way to do this without calling "bash -c" (e.g., creative use of parentheses)? | |
| Jun 1, 2012 at 19:39 | history | answered | Dennis Williamson | CC BY-SA 3.0 |