[Q] CyanogenMod 10.2 su ctrl-character input - Nexus 7 (2013) Q&A

Can't post in the CyanogenMod thread where this really belongs, but I'm still on restriction.
I use the shell and su command extensively. On any Android Terminal Emulator derived app (Term.apk and AirTerm), when executing su the stty settings get hosed. I lose tab completion (tab is just a tab). All control characters get echoed, rather than executing their properly bound function. For example, I type ctrl-p, and I see ^P, rather than moving up in the command history. And if I type ctrl-C, the shell actually quits. And the final capper, is when using ssh from an su shell, the Password field echoes the password!
Any attempt to change stty setting show up as changed, but have no affect. But the main thing I see on an stty -a is the line:
Code:
Prior to executing su...
% stty -a
speed 38400 baud; rows 19; columns 80; line = 2;
....
After executing su
% su
# stty -a
stty -a
speed 38400 baud;stty: standard input
line = 0;
....
Note that the stty -a is echoed and then executed in the second case. The "stty: standard input" looks to be the problem (it isn't supposed to say that), and I'm pretty sure the su caused this.
Executing su -v returns a version of "12 com.android.settings."
Any advice appreciated.
-Pie

Same here, it's really annoying.

Related

[Q] Call Tracing on Android

I have two questions:
1) I am using strace on the Android emulator to track system calls of running apps. I keep getting this error line: “ptrace: umoven: I/O error” in the adb shell window. Although I can collect the traces this error is bugging me. Why do I get this error and how can I remove it? Here is the command I execute:
strace -p <PID> -F -f -ttt -o <outputfile>
2) I want to use ftrace and ltrace on the emulator too. I could not find any instructions or source files for these. For ltrace I tried to cross-compile the source files and I got the following error: "gelf.h not found". For ftrace I have no clue at all.
Please help.

[SOLVED] Shell scripting problem: unexpected "fi"

SOLVED: The file had Windows EOL formatting. *nix no likely that.
In the init script there are several instances of if statements like this:
Code:
testvar=1
if [ "$testvar" = "1" ] ; then
echo "Testvar is equal to one"
fi
Yet, when I put if statements exactly like this into a shell script and execute them in an adb shell (or connectbox shell), I get the following error:
line 4: syntax error: unexpected "fi" (expecting "then")
I've also taken if statements directly from init and they throw the same error.
Any busybox gurus here know what's up with this?
toadlife said:
In the init script there are several instances of if statements like this:
Code:
testvar=1
if [ "$testvar" = "1" ] ; then
echo "Testvar is equal to one"
fi
Yet, when I put if statements exactly like this into a shell script and execute them in an adb shell (or connectbox shell), I get the following error:
line 4: syntax error: unexpected "fi" (expecting "then")
I've also taken if statements directly from init and they throw the same error.
Any busybox gurus here know what's up with this?
Click to expand...
Click to collapse
Remove the ; and enter the then
Code:
testvar=1
if [ "$testvar" = "1" ]
then
echo "Testvar is equal to one"
fi
Nope. Still throws the same error.
This is driving me nuts. What I'm doing is editing the /init script. The loops work just fine when executed at bootup in / init, but remounting the filesystem, editing /init and rebooting just the test a change takes forever.
For now I've got my changes to init working, but it would be nice to be able to test before editing /init
I just realized that I forgot to put `#!/bin/sh` at the top of my script. But doing so doesn't seem to help. Instead I get not found error.
Weird!
toadlife said:
Nope. Still throws the same error.
This is driving me nuts. What I'm doing is editing the /init script. The loops work just fine when executed at bootup in / init, but remounting the filesystem, editing /init and rebooting just the test a change takes forever.
For now I've got my changes to init working, but it would be nice to be able to test before editing /init
Click to expand...
Click to collapse
Code:
testvar=1
if [ $testvar = `1` ] (`=~ key)
then
echo "Testvar is equal to one"
fi
[/QUOTE]
It gives the echo, but also 1: not found.
Here is the actual code I put into my init:
(this works)
Code:
#Super cool battery thingy
RUNSCBS=`/bin/grep -o "run.scbs=.*" /proc/cmdline | /bin/sed -e "s/.*run.scbs=//g" -e "s/ .*//g"`
if [ "$RUNSCBS" = "1" ] ; then
dev=$(cat /sys/class/scbs/0/dev | sed -e "s/:/ /g")
mknod /dev/scbs0 c $dev
scbs -d -co /sdcard/scbs.conf
fi
# Debug logs
TAKELOGS=`/bin/grep -o "take.logs=.*" /proc/cmdline | /bin/sed -e "s/.*take.logs=//g" -e "s/ .*//g"`
if [ "$TAKELOGS" = "1" ] ; then
logfiledate=`expr substr \`date -Iseconds|tr -d :|tr -d \+|tr -d \-|tr -d T\` 1 14`
tar -cz -f "$card"/debuglogs_"$logfiledate".tar.gz "$card"/debuglogs_*.txt
cat /proc/kmsg>"$card"/debuglogs_kmsg_"$logfiledate".txt &
logcat -v time >"$card"/debuglogs_logcat_time_"$logfiledate".txt &
logcat -v time -b radio>"$card"/debuglogs_logcat_time_radio_"$logfiledate".txt &
fi
Ooooo I really like the idea of having logging running from init. Does that work well? Do the logs ever 'loop' and you end up missing things, or do they just keep on churnin?
arrrghhh said:
Ooooo I really like the idea of having logging running from init. Does that work well? Do the logs ever 'loop' and you end up missing things, or do they just keep on churnin?
Click to expand...
Click to collapse
AFAIK, they go forever. I started doing it last night by just putting the static command in the /init and the logging was still going when I got up this morning.
This morning wanted to see if I could make logging and scbs triggerable by an option in the command line.
Both are working for me now.
Know if where talking about scripts, i have a question too.
This is my RIL logs script:
Code:
#! /system/bin/sh
i="0"
while [ $i -lt 2 ]
do
date=`date +%Y%m%d%H%M`
if [ -d /sdcard/logs/ril/$date/ ]
then
echo "/sdcard/logs/ril/$date/ exists!"
else
mkdir /sdcard/logs/ril/$date/
echo " Made direction /sdcard/logs/ril/$date!"
fi
logcat -v time > /sdcard/logs/ril/$date/logcat-time.txt &
logcat -v time -b radio > /sdcard/logs/ril/$date/logcat-time.txt &
sleep 18000 && kill -0 $! && kill $!
cd /sdcard/logs/ril/
tar -czf ril$date.tar.gz $date
rm -r $date
cd /
done
The thing, i believe, is that only the logcat -v time -b radio is killed and when it's sleeping it's not doing that in the background.
Sleeping for 18000 seconds (5h), because if it's running for a day the logcat log will be more than 10 mb or so.
lol.
Your date string...
Code:
date +%Y%m%d%H%M
...is a bit simpler than mine...
Code:
expr substr `date -Iseconds|tr -d :|tr -d \+|tr -d \-|tr -d T` 1 14
(I couldn't figure out the `date` syntax)
Christiaan91 said:
Know if where talking about scripts, i have a question too.
This is my RIL logs script:
Code:
#! /system/bin/sh
i="0"
while [ $i -lt 2 ]
do
date=`date +%Y%m%d%H%M`
if [ -d /sdcard/logs/ril/$date/ ]
then
echo "/sdcard/logs/ril/$date/ exists!"
else
mkdir /sdcard/logs/ril/$date/
echo " Made direction /sdcard/logs/ril/$date!"
fi
logcat -v time > /sdcard/logs/ril/$date/logcat-time.txt &
logcat -v time -b radio > /sdcard/logs/ril/$date/logcat-time.txt &
sleep 18000 && kill -0 $! && kill $!
cd /sdcard/logs/ril/
tar -czf ril$date.tar.gz $date
rm -r $date
cd /
done
The thing, i believe, is that only the logcat -v time -b radio is killed and when it's sleeping it's not doing that in the background.
Sleeping for 18000 seconds (5h), because if it's running for a day the logcat log will be more than 10 mb or so.
Click to expand...
Click to collapse
Hmm. I haven't set up gscript myself yet, but you might need to nohup the logcats to get them to stay once gscript shuts down.
arrrghhh said:
Ooooo I really like the idea of having logging running from init. Does that work well? Do the logs ever 'loop' and you end up missing things, or do they just keep on churnin?
Click to expand...
Click to collapse
I have found one issue. It's seems that whenever scbs runs, locat fails to open the log devices. I just disabled scbs and logcat worked. I'm going to try swapping the code around so scbs runs after the logging starts.
It seems scbs blows up logcat, even when it is triggered after logging starts. Ughhh.
Entropy512 said:
Hmm. I haven't set up gscript myself yet, but you might need to nohup the logcats to get them to stay once gscript shuts down.
Click to expand...
Click to collapse
logcat will be going, even when you close the terminal, but when you deleted the files they stop. So that's not a problem, cuz i won't delete.
BTW: is it possible to silently run scripts? Like this one?
./pathtoscript1 & ./pathtoscript2 & ./pathtoscript3
Christiaan91 said:
logcat will be going, even when you close the terminal, but when you deleted the files they stop. So that's not a problem, cuz i won't delete.
BTW: is it possible to silently run scripts? Like this one?
./pathtoscript1 & ./pathtoscript2 & ./pathtoscript3
Click to expand...
Click to collapse
What do you mean "silently run" - do you mean disable any printing to stdout?
./pathtoscript1 &>/dev/null & ; ./pathtoscript2 &>/dev/null &
should do the trick The &>/dev/null routes all output to /dev/null
Man, you guys go way overboard on this stuff. This is my gscript logging script.
Code:
cd /sdcard
mv logg.txt logg.0.txt
mv logr.txt logr.0.txt
nohup logcat -v time > logg.txt &
nohup logcat -v time -b radio > logr.txt &
nohup klogd > klog.txt
highlandsun said:
Man, you guys go way overboard on this stuff. This is my gscript logging script.
Code:
cd /sdcard
mv logg.txt logg.0.txt
mv logr.txt logr.0.txt
nohup logcat -v time > logg.txt &
nohup logcat -v time -b radio > logr.txt &
nohup klogd > klog.txt
Click to expand...
Click to collapse
Yeah, well we don't all have kung-fu coding ablities like you, so we go overboard with what we can overboard with.
Besides, I think it might be beneficial to put something like the code I wrote into the official init, so noobs can more easily provide debug logs.
One thing to keep in mind, busybox = /bin/sh, statically compiled sh is /system/bin/sh. I got tired of not having arrow key support whenever I su'ed (since /bin/su spawns a root /system/bin/sh regardless of what's in /etc/passwd) so I bind mounted /bin/sh (which is a symlink to busybox) over the one in /system in my user.conf. I haven't come across any ill effect, but if you feel that the shell difference may be causing issues, you could try that route, since it's very easy to undo.
-- Starfox
Starfox said:
One thing to keep in mind, busybox = /bin/sh, statically compiled sh is /system/bin/sh. I got tired of not having arrow key support whenever I su'ed (since /bin/su spawns a root /system/bin/sh regardless of what's in /etc/passwd) so I bind mounted /bin/sh (which is a symlink to busybox) over the one in /system in my user.conf. I haven't come across any ill effect, but if you feel that the shell difference may be causing issues, you could try that route, since it's very easy to undo.
-- Starfox
Click to expand...
Click to collapse
Thanks for the tip. I'll give that a shot.
LOL. I'm an idiot
Figured out what the problem was. The file had Windows EOL formatting.
That's what I get for using Windows to edit shell scripts.

[Q] Setting up aliases for shell commands

Hello,
I have a question about linux shell command aliases in Android:
Is it possible to set up permanent aliases that can be used from both a terminal emulator on the device as well as ADB?
When I define an alias using adb, its gone as soon as I exit that session... but I would really like to have some permanent aliases for things I often use...
For example: "ls -la --color=never" is a bit tough to type everytime, but otherwise the color codes will screw up the adb shell output...
Any help appreciated!
Found a solution.
If anyone is interested:
Download bash posted in this thread: http://forum.xda-developers.com/showthread.php?t=537827
Adb push this bash to /system/bin, set permissions to 755 and symlink ./sh to ./bash...
Actually, instructions are all in the other thread
Then you can put your bashrc file to /sdcard/bash_profile, done!
It took me some searching but I found out how. Just add your aliases to the bottom of /system/etc/mkshrc

The Android Shell

The Android Shell
A "shell" is a program that listens to keyboard input from a user and performs actions as directed by the user. Android devices come with a simple shell program. This shell program is mostly undocumented. Since many people are curious about it I thought I'd write up some documentation for it.
Currently this documentation is incomplete, sorry!
Common problems
The built-in shell has very limited error handling. When you type a command name incorrectly it will say "permission denied", even though the real problem is that it couldn't find the command:
$ dir
dir: permission denied <---- this is a misleading error message, should say 'dir: not found'
$ ls
... listing of current directory
The PATH variable
The Android shell will run any program it finds in its PATH. The PATH is a colon (':') seperated list of directories. You can find out what your shell's PATH is set to by using the built-in echo command:
$ echo $PATH
/data/local/bin:/sbin:/vendor/bin:/system/sbin:/system/bin:/system/xbin
Depending upon your shell, you may see a different result.
Built in Commands
Every shell has a few built-in commands. Some common built-in commands are:
echo -- prints text to stdout.
set -- sets shell variables
export -- makes shell variables available to command-line programs
cd -- change the current directory.
pwd -- print name of the current directory.
Commands
To find out what commands you have available to you, use the "ls" command on each of the directories in the PATH variable.
Finding documentation for the Android commands.
Many of the Android commands are based on standard Linux (or bsd) commands. If you're curious about a command, you can sometimes learn how it works by using the "man" command on a desktop Linux or OSX (Apple Macintosh) computer. The Linux or OSX version of the command may be different in details, but much of the documentation will still apply to the Android version of the command.
Another source of documentation for people without a Linux or OSX machine handy is to use a web browser and use a web search engine to search for the text: "man Linux command-name".
List of commands
The following is a list of the commands that are present on a Nexus S phone running an Android 2.3.3 "user-debug" build. Many of these commands are not present on a "user" phone. (They are missing from a "user" phone because they are specific to developing or debugging the Android operating system.)
$ ls /data/local/bin
/data/local/bin: No such file or directory
Notice that by default there is no /data/local/bin directory. You can create this directory using the "mkdir" command if you like.
$ ls /sbin
opendir failed, Permission denied
The /sbin directory exists, but you don't have permission to access it. You need root access. If you have a developer phone, or otherwise have root access to your phone you can see what's in this directory.
$ su
# ls /sbin
ueventd
adbd
# exit
$
Notice that the shell prompt changes from a '$' to a '#' to indicate that you have root access.
Notice also that neither of the /sbin commands are useful to the shell -- the adb and ueventd files are 'daemon' programs used to implement the Android Debugger "adb" program that is used by developers.
$ ls /vendor/bin
gpsd
pvrsrvinit
Vendor/bin is where device vendors can put device-specific executables. These files are from a Nexus S.
$ ls /system/sbin
/system/sbin: No such file or directory
This directory does not exist on a Nexus S.
$ ls /system/bin
am
am is the Android Activity Manager. It's used to start and stop Android activities (e.g. applications) from the command line. Type am by itself to get a list of options.
amix
aplay
Command line audio file player.
app_process
applypatch
Used to apply patches to android files.
arec
Command line audio recorder.
audioloop
bluetoothd
BlueTooth daemon
bmgr
Backup manager - type command by itself to get documentation.
bootanimation
Draws the boot animation. You may have to reset your phone to get out of this.
brcm_patchram_plus
bugreport
cat
Copy the contents of a file to standard output.
chmod
Change the mode of a file (e.g. whether it can be read or written.)
chown
Change the owner of a file.
cmp
Compare two files byte-by-byte
dalvikvm
The dalvik virtual machine. (Used to run Android applications.)
date
Prints the current date and time
dbus-daemon
dd
Convert and copy a file. By default copies standard in to standard out.
debuggerd
dexopt
df
Shows how much space is free on different file systems on your device.
dhcpcd
dmesg
dnsmasq
dumpstate
dumpsys
dvz
fsck_msdos
gdbserver
getevent
getprop
gzip
hciattach
hd
id
ifconfig
Shows the current configuration of network interfaces (IP, MAC address etc)
iftop
Shows the current processes using the network interfaces (top, but for networks)
ime
input
insmod
installd
ioctl
ionice
iptables
Manage the firewall
keystore
keystore_cli
kill
Send signals to processes.
linker
ln
Used to set up a file system link.
log
logcat
Prints the Android runtime log.
logwrapper
ls
Lists files.
lsmod
lsof
make_ext4fs
mediaserver
mkdir
Make a directory.
monkey
A program that sends random events, used to test applications. (Like having a monkey playing with the device.)
mount
mtpd
mv
Move a file from one directory to another. (Only on the same file system. Use "cat a > b" to copy a file between file systems.
nandread
ndc
netcfg
netd
netstat
newfs_msdos
notify
omx_tests
pand
ping
pm
pppd
printenv
ps
List active processes.
qemu-props
qemud
racoon
radiooptions
reboot
Reboot the device.
record
renice
rild
rm
Remove a file.
rmdir
Remove a directory.
rmmod
route
rtp_test
run-as
schedtest
schedtop
sdcard
sdptool
sendevent
service
servicemanager
setconsole
setprop
setup_fs
sh
showlease
sleep
smd
stagefright
start
Starts the Android runtime.
stop
Stops the Android runtime.
surfaceflinger
svc
sync
system_server
tc
testid3
toolbox
top
Shows which processes are currently using the most CPU time.
umount
uptime
Prints how long your device has been running since it was last booted.
vdc
vmstat
vold
watchprops
wipe
wpa_cli
wpa_supplicant
$ ls /system/xbin
add-property-tag
btool
check-lost+found
dexdump
dhdutil
hcidump
latencytop
librank
opcontrol
oprofiled
procmem
procrank
rawbu
scp
Secure copy program. (Used to copy files over the network.)
showmap
showslab
sqlite3
Used to administer SQLite databases.
strace
System trace command - use to see what system calls a program makes.
su
Start a shell with root privileges.
Versions of the Android Shell
Android 1.0 used a shell that had no tab completion or history editing.
Android 2.3 added history editing. You can for example use the up/down arrows to edit previous commands.

how do I read and write the framebuffer screen without errors?

I get this:
Code:
[email protected]:/ # cat /dev/urandom > /dev/graphics/fb0
tmp-mksh: cat: <stdout>: No space left on device
or with direct access
Code:
[email protected]:/ # ln -n /dev/graphics/fb0 /dev/fb0
[email protected]:/ # cat /dev/urandom > /dev/fb0
tmp-mksh: cat: <stdout>: No space left on device
How do I do it?
The error is normal and the expected behaviour because you are writing more data to the framebuffer than actually fits on it.
However I assume you see no change to the displayed image despite writing to the framebuffer. (I see no change on my display.)
I think this might be because surfaceflinger takes full control of the framebuffer and replaces the static noise (caused by cat /dev/urandom) with a composited android screen image before refreshing the screen.
As for the correct way to write to the framebuffer:
I think you need to kill surfaceflinger first (and make sure it doesn't restart) and then use the cat command(though the error will remain). Alternatively you can write a small program in C that does the same by opening fb0, mapping it to memory and then writing onto that.
To read from fb0, a simple "cat /dev/graphics/fb0 > /sdcard/fbimage" should work.
However I am not too sure about most of this.

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