Develop Reference

Execute multiple adb shell command in bash script [duplicate]

I'm writing a simple Bash script that simply the call of HadnBrakeCli for render videos.
I also implemented a simple queue option: the queue file just store the line-command it has to call to start a render.
So I wrote a while-loop to read one line at time, eval $line and repeat untill file ends.
if [[ ${QUEUE_MODE} = 'RUN' ]]; then
QUEUE_LEN=`cat ${CONFIG_DIR}/queue | wc -l`
QUEUE_POS='1'
printf "Queue lenght:\t ${QUEUE_LEN}\n"
while IFS= read line; do
echo "--Running render ${QUEUE_POS} on ${QUEUE_LEN}..."
echo "++" && echo "$line" && echo "++"
eval "${line}"
tail -n +2 "${CONFIG_DIR}/queue" > "${CONFIG_DIR}/queue.tmp" && mv "${CONFIG_DIR}/queue.tmp" "${CONFIG_DIR}/queue"
echo "--Render ended"
QUEUE_POS=`expr $QUEUE_POS + 1`
done < "${CONFIG_DIR}/queue"
exit 0
The problem is that any command makes the loop to work fine (empty line, echo "test"...), but as soon a proper render is loaded, it is launched and finished correctly, but also the loops exists.
I am a newbie so I tried some minor changes to see what effect I got, but nothing change the result.
I commented the command tail -n +2 "${CONFIG_DIR}/queue" > "${CONFIG_DIR}/queue.tmp" && mv "${CONFIG_DIR}/queue.tmp" "${CONFIG_DIR}/queue" or I added/removed IFS= in the while-loop or removed the -r in read command.
Sorry if the question is trivial, but I'm really missing some major part in how it works, so I have no idea even how to search for the solution.
I'll put a sample of a general render in the queue file.
HandBrakeCLI -i "/home/andrea/Videos/done/Rap dottor male e mini me.mp4" -o "/hdd/Render/Output/Rap dottor male e mini me.mkv" -e x265 -q 23 --encoder-preset faster --all-audio -E av_aac -6 dpl2 --all-subtitles -x pmode:pools='16' --verbose=0 2>/dev/null

HandBrakeCLI reads from standard input, which steals the rest of the queue file before read line can see it. My favorite solution to this is to pass the file over something other than standard input, like file descriptor #3:
...
while IFS= read line <&3; do # The <&3 makes it read from FD #3
...
done 3< "${CONFIG_DIR}/queue" # The 3< redirects the file into FD #3
Another way to avoid the problem is to redirect input to the HandBrakeCLI command:
...
eval "${line}" </dev/null
...
There's some more info about this in BashFAQ #89: I'm reading a file line by line and running ssh or ffmpeg, only the first line gets processed!
Also, I'm not sure I trust the way you're using tail to remove lines from the queue file as they're executed. I'm not sure it's really wrong, it just looks fragile to me. Also, I'd recommend using lower- or mixed-case variable names, since there are a bunch of all-caps names with special meanings, and re-using one of them by mistake can have weird consequences. Finally, I'd recommend running your script through shellcheck.net, as it'll make some other good recommendations.
[BTW, this question is a duplicate of "Bash script do loop exiting early", but that doesn't have any upvoted or accepted answers.]

How to return 0 if a pattern is matched from a file?

I have a binary that repacks android kernel (not mkbootimg).
I'm making a script to automate the process.
I don't want any output on the screen. So I have redirected the output to a file named foo.log.
My current working folder is data/local/working/.
The command is - kernel_make "$zImage" "$ramdisk" "$cmdline" "$image" &> data/local/working/foo.log
What I've to do is, if the last line of the output (foo.log) is this -
"targed file $1 is patched sucesfully, enjoy new kernel"
Then return 0 and exit. Else return 1 and exit.
I'm trying to do with grep, but as I'm new to command line, do don't have any idea of doing it the right way.
Please be free to ask if anything more is required..

a common usage for that would be grep -q 'pattern', it doesn't generate any output, but you can check the return value of the command to decide if the pattern was found. See this example:
kent$ echo "foo"|grep -q bar
kent$ echo $?
1
kent$ echo "bar"|grep -q bar
kent$ echo $?
0
hope this is what you are looking for.
To extract the last line, you can use tail command.
In fact, you can also do it with awk in one shot:
..cmd with..output|awk 'END{if (!/pattern/)exit 1}'
then you can check the $?

Why is nohup still causing a process being run in a shell script to terminate?

I am logging the data coming from top and putting it into a circular set of files. I am not executing top for one set of data and then rerunning for the next set, but instead using a read time out to specify when to go from one log file to the next. This is primarily done this way to remove the startup CPU load cost every time top is executed. The shell script file's name is toplog.sh and looks similar to this:
#!/data/data/com.spartacusrex.spartacuside/files/system/bin/bash
date
echo " Logging started."
fileCmp()
{
test `ls -lc "$1" | sed -n 's/\([^ ]* *\)\{4\}\([0-9]*\).*$/\2/;p'` $2 $3
}
oldest()
{
ls -rc $1 2> /dev/null |head -1
}
file=`oldest /mnt/sdcard/toplog.\*.gz`
echo " Oldest file is $file"
if [ -z "$file" ]; then
x=0
else
file=${file%%.gz}
file=${file##*.}
x=$file
fi
echo " x=$x"
top -d 20 -b | \
while true; do
file=/mnt/sdcard/toplog.$x.gz
while read -t 5 line; do
echo "$line"
done | gzip -c > $file
if fileCmp "$file" -le 300; then
date
echo " Failure to write to file '$file'."
exit
fi
x=$((($x+1)%10))
sleep 14
done
I execute this using nohup so that when the shell dies, this process still runs, like so:
$ nohup ./toplog.sh
But there's a problem. top terminates when I exit the shell session that executed that command, and I'm not exactly sure why. Any ideas?
To clarify, I'm logging on a Android phone. The tools are limited in functionality (i.e. lack some of these switches) and is why I am using top as it contains the output I want.
Version of busybox I'm using is:
BusyBox 1.19.2 (2011-12-12 12:59:36 GMT)
Installed when I installed Terminal IDE.
BTW, this phone is not rooted. I'm trying to track down a failure when my phone responds as if the CPU has spiked and won't go down.
Edit:
Well, I found a workaround. But the reason is a bit hazy. I think it has to do with process management and smells of a bug in the busybox ver that I'm using that was missed during regression testing.
The workaround is to wrap top with a useless loop structure like this: while true; do top; done. Through testing, top never gets killed and never gets respawned, but by wrapping it up, it isn't killed.
Any insights on this?

going to sound stupid, but change your startup command from
nohup ./toplog.sh
to
nohup ./toplog.sh &
the & makes it run as a background process further removing it from the terminal stack.

Running the bash internal command "disown" on your script's process before logging off may prevent it from being signaled.

Time cannot run brunch?

I'm having an issue with the time command.
I use /usr/bin/time so i can use the -f and -o modifiers.
My script is:
make clean
repo sync -j5
. ./platform_manifest/manual_add_kernel_manifest.sh \
&& . build/envsetup.sh \
&& /usr/bin/time -o log$day$month.log -f "Buildtime: %E" brunch aokp_mako-eng
The script is part of an automated build system for an android ROM.
When it gets to the time part, i get:
/usr/bin/time: cannot run brunch: No such file or directory
Command exited with non-zero status 127
Buildtime: 0:00.00
Brunch works fine with the regular time command, but I cannot route its output to a file, which is why I am using /usr/bin/time in the first place. If there is a way to do this, that is fine for me as I can trim off the real: header with | awk '{ print $2 }'.
Any help is appreciated!
Ubuntu 12.04, all updates installed

I don't know what brunch is, but the most likely reason that a non-builtin time program can't find it, even when the built-in time can, is that it's a shell function or a Bash alias.
Whether or not that's the case . . .
[…] I cannot route [the regular time command's] output to a file […]
You can write:
{ time brunch aokp_mako-eng ; } 2>"log$day$month.log"
to wrap time (and everything else) into a command-list whose STDERR has already been redirected to the file.

shell script in android gives [: not found

I have this script which works on my linux machine
#!/bin/sh
c=1
if [ $c == 1 ]
then
echo c is 1
else
echo c is 0
fi
But when I use this in android as follows:
#!/system/bin/sh
c=1
if [ $c == 1 ]
then
echo c is 1
else
echo c is 0
fi
It gives an error like:
[: not found
EDIT
Is there any other logic to check the value of $c, whether it is 1 or 0 ?
Android shell have problem with [] in if so is there any other way to check the value of c ?

andriod shell sh is actually a link to busybox, and it is invoked as
busybox sh
you need setup [ applets manually
busybox ln -s /your_original_sh_path/busybox [
if you don't know where busybox is put, try list the /system/bin/sh which you give
ls /system/bin/sh
busybox which busybox

generally [ is an alias for test,
in Linux machine test is at
/usr/bin/test
and
if [ $c == 1 ]
is evaluated as
if test "$c" = 1
BUT here in android there is no test
so if with [] will not work in any case...
i will cross compile test for android and check it....!!!

Android does not provide a full UNIX environment, it is not a UNIX operating system. It has some similarities, much like how Windows also has some similarities to UNIX. Some Android devices and ROMs try to provide more of a UNIX-like environment that others, but you cannot rely on most of the standard shell scripting tools being installed if you are thinking about cross-device compatibility.
So for example, if you look at your GNU/Linux system, you can see that test and [ are actually programs. Try this: ls -l /usr/bin/[. Most Android installs do not include test or [. That means that if you want to try to do actual programming with Android's minimal shell environment, you have to use lots of odd tricks. You can install busybox to get a full UNIX shell environment, or you can even build busybox into your app. I do that when I need to include shell scripts in an app (for example, Lil' Debi and Commotion MeshTether).
Here's an example of writing a killall in Android's /system/bin/sh environment: http://en.androidwiki.com/wiki/Android_Shell_tips_and_tricks You can also use the various parameter expansions to create some logic, you can see an example of that in the Barnacle Wifi Tether scripts.

Use bash:
#!/system/bin/bash
or
#!/system/xbin/bash
You can check where your sh binary is pointing to on your Linux machine:
ls -l /bin/sh
Edit
BTW, use:
c=1
if [ $c -eq 1 ]
then
echo c is 1
else
echo c is 0
fi

Think you using the wrong arithmetic operator and there is a syntax error of a missing ";": try
[ $c -eq 1 ];
Also your location for Bash (sh) might be wrong at the top of your file:
#!/system/bin/sh

How about checking that the .sh file doesn't contain a carriage return before line feed.
Windows \r\n -> CR LF
Unix \n -> LF

use /system/bin/cmp for equality test.
if you need numerically test, substitute $(($c == 1)) with $c
#!/system/bin/sh
echo $c >/tmp/a
echo 1 >/tmp/b
if cmp /tmp/a /tmp/b
echo c is 1
else
echo c is 0
fi

I run into this issue also and found a solution (on another site)
if [[ $b -gt 0]]
then
echo 'Hooray it works'
else
echo 'still works'
fi