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Mkbootfs writing to stdout in bash script

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# 8  
Old 04-17-2013
That is very odd. If that really is the code, there's no reason at all for it to do that... I suspect your version ended up a little different somehow, but would need to use strace or something to tell what it's really doing.

The trick with nohup may also help narrow it down.

It's also possible there's more than one mkbootfs, and due to PATH differences your shell runs one and your script runs the other!
This User Gave Thanks to Corona688 For This Post:
Phil3759
# 9  
Old 04-17-2013
Sure, I use that source to compile it along cyanogenmod source
No error about the called binary as I use full path to call it, not in PATH var

Here's the output from nohup you asked for

Shell:
Code:
#!/bin/bash
nohup /root/Desktop/build_cm10/android_cm-10.1/system/out/host/linux-x86/bin/mkbootfs /root/Desktop/build_cm10/android_cm-10.1/system/out/target/product/n7100/recovery/root > /root/Desktop/build_cm10/android_cm-10.1/system/out/target/product/n7100/ramdisk-recovery.cpio

Code:
nohup: ignoring input and redirecting stderr to stdout


It created the cpio file with correct content Smilie

While nohup works while not my redirection usual rules?
# 10  
Old 04-17-2013
It is a mystery. It really shouldn't do that.

Show me the exact line that didn't work please -- unabridged, no substitutions, exactly as you had it. The entire script, even. There may be context missing, something before that line which changed the meaning of your redirection.
This User Gave Thanks to Corona688 For This Post:
Phil3759
# 11  
Old 04-17-2013
Well,
Thanks to you, I could repeat and reproduce the exact issue cause. Here's what I messed with:

In fact, after only removing nohup from exactly above script, my script still works perfectly

Now, the below script will trigger the issue

Code:
#!/bin/bash
CMD_LINE1="/root/Desktop/build_cm10/android_cm-10.1/system/out/host/linux-x86/bin/mkbootfs /root/Desktop/build_cm10/android_cm-10.1/system/out/target/product/n7100/recovery/root > /root/Desktop/build_cm10/android_cm-10.1/system/out/target/product/n7100/ramdisk-recovery.cpio"

$CMD_LINE1

So, it seems the cause is putting the command line into a variable and trying to run it that way, which causes output to stdout
Should I have used exec or similar to do it that way?
# 12  
Old 04-17-2013
You can see what is happening, why it does not work, if you use "set -x" at the top of the shell script.

Unless there is some good reason (can't think of any), do not try putting an entire command line, including redirection, into a variable.

I would suggest the following, to improve readability, to get rid of extremely long line which is maybe causing confusion:
Code:
dir=/root/Desktop/build_cm10/android_cm-10.1/system/out
   cmd=$dir/host/linux-x86/bin/mkbootfs
 input=$dir/target/product/n7100/recovery/root
output=$dir/target/product/n7100/ramdisk-recovery.cpio
$cmd $input > $output

This User Gave Thanks to hanson44 For This Post:
Phil3759
# 13  
Old 04-18-2013
Quote:
Originally Posted by hanson44
You can see what is happening, why it does not work, if you use "set -x" at the top of the shell script.

Unless there is some good reason (can't think of any), do not try putting an entire command line, including redirection, into a variable.

I would suggest the following, to improve readability, to get rid of extremely long line which is maybe causing confusion:
Code:
dir=/root/Desktop/build_cm10/android_cm-10.1/system/out
   cmd=$dir/host/linux-x86/bin/mkbootfs
 input=$dir/target/product/n7100/recovery/root
output=$dir/target/product/n7100/ramdisk-recovery.cpio
$cmd $input > $output

I will try it and report back, thanks
# 14  
Old 04-18-2013
Yes, "set -x" can be pretty useful. It can create a lot of output, which can be difficult to wade through. But for the most part "set -x" shows what is going on, what the shell "sees".
This User Gave Thanks to hanson44 For This Post:
Phil3759
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