I am making an NW.js app on macOS, and want to run the app in dev mode
by double-clicking on an icon.
In the first step, I'm trying to make my shell script work.
Using VS Code on Windows (I wanted to gain time), I have created a run-nw file at the root of my project, containing this:
#!/bin/bash
cd "src"
npm install
cd ..
./tools/nwjs-sdk-v0.17.3-osx-x64/nwjs.app/Contents/MacOS/nwjs "src" &
but I get this output:
$ sh ./run-nw
: command not found
: No such file or directory
: command not found
: No such file or directory
Usage: npm <command>
where <command> is one of: (snip commands list)
(snip npm help)
npm#3.10.3 /usr/local/lib/node_modules/npm
: command not found
: No such file or directory
: command not found
Some things I don't understand.
It seems that it takes empty lines as commands.
In my editor (VS Code) I have tried to replace \r\n with \n
(in case the \r creates problems) but it changes nothing.
It seems that it doesn't find the folders
(with or without the dirname instruction),
or maybe it doesn't know about the cd command ?
It seems that it doesn't understand the install argument to npm.
The part that really weirds me out, is that it still runs the app
(if I did an npm install manually)...
Not able to make it work properly, and suspecting something weird with
the file itself, I created a new one directly on the Mac, using vim this time.
I entered the exact same instructions, and... now it works without any
issues.
A diff on the two files reveals exactly zero difference.
What can be the difference? What can make the first script not work? How can I find out?
Update
Following the accepted answer's recommendations, after the wrong line
endings came back, I checked multiple things.
It turns out that since I copied my ~/.gitconfig from my Windows
machine, I had autocrlf=true, so every time I modified the bash
file under Windows, it re-set the line endings to \r\n.
So, in addition to running dos2unix (which you will have to
install using Homebrew on a Mac), if you're using Git, check your
.gitconfig file.
Yes. Bash scripts are sensitive to line-endings, both in the script itself and in data it processes. They should have Unix-style line-endings, i.e., each line is terminated with a Line Feed character (decimal 10, hex 0A in ASCII).
DOS/Windows line endings in the script
With Windows or DOS-style line endings , each line is terminated with a Carriage Return followed by a Line Feed character. You can see this otherwise invisible character in the output of cat -v yourfile:
$ cat -v yourfile
#!/bin/bash^M
^M
cd "src"^M
npm install^M
^M
cd ..^M
./tools/nwjs-sdk-v0.17.3-osx-x64/nwjs.app/Contents/MacOS/nwjs "src" &^M
In this case, the carriage return (^M in caret notation or \r in C escape notation) is not treated as whitespace. Bash interprets the first line after the shebang (consisting of a single carriage return character) as the name of a command/program to run.
Since there is no command named ^M, it prints : command not found
Since there is no directory named "src"^M (or src^M), it prints : No such file or directory
It passes install^M instead of install as an argument to npm which causes npm to complain.
DOS/Windows line endings in input data
Like above, if you have an input file with carriage returns:
hello^M
world^M
then it will look completely normal in editors and when writing it to screen, but tools may produce strange results. For example, grep will fail to find lines that are obviously there:
$ grep 'hello$' file.txt || grep -x "hello" file.txt
(no match because the line actually ends in ^M)
Appended text will instead overwrite the line because the carriage returns moves the cursor to the start of the line:
$ sed -e 's/$/!/' file.txt
!ello
!orld
String comparison will seem to fail, even though strings appear to be the same when writing to screen:
$ a="hello"; read b < file.txt
$ if [[ "$a" = "$b" ]]
then echo "Variables are equal."
else echo "Sorry, $a is not equal to $b"
fi
Sorry, hello is not equal to hello
Solutions
The solution is to convert the file to use Unix-style line endings. There are a number of ways this can be accomplished:
This can be done using the dos2unix program:
dos2unix filename
Open the file in a capable text editor (Sublime, Notepad++, not Notepad) and configure it to save files with Unix line endings, e.g., with Vim, run the following command before (re)saving:
:set fileformat=unix
If you have a version of the sed utility that supports the -i or --in-place option, e.g., GNU sed, you could run the following command to strip trailing carriage returns:
sed -i 's/\r$//' filename
With other versions of sed, you could use output redirection to write to a new file. Be sure to use a different filename for the redirection target (it can be renamed later).
sed 's/\r$//' filename > filename.unix
Similarly, the tr translation filter can be used to delete unwanted characters from its input:
tr -d '\r' <filename >filename.unix
Cygwin Bash
With the Bash port for Cygwin, there’s a custom igncr option that can be set to ignore the Carriage Return in line endings (presumably because many of its users use native Windows programs to edit their text files).
This can be enabled for the current shell by running set -o igncr.
Setting this option applies only to the current shell process so it can be useful when sourcing files with extraneous carriage returns. If you regularly encounter shell scripts with DOS line endings and want this option to be set permanently, you could set an environment variable called SHELLOPTS (all capital letters) to include igncr. This environment variable is used by Bash to set shell options when it starts (before reading any startup files).
Useful utilities
The file utility is useful for quickly seeing which line endings are used in a text file. Here’s what it prints for for each file type:
Unix line endings: Bourne-Again shell script, ASCII text executable
Mac line endings: Bourne-Again shell script, ASCII text executable, with CR line terminators
DOS line endings: Bourne-Again shell script, ASCII text executable, with CRLF line terminators
The GNU version of the cat utility has a -v, --show-nonprinting option that displays non-printing characters.
The dos2unix utility is specifically written for converting text files between Unix, Mac and DOS line endings.
Useful links
Wikipedia has an excellent article covering the many different ways of marking the end of a line of text, the history of such encodings and how newlines are treated in different operating systems, programming languages and Internet protocols (e.g., FTP).
Files with classic Mac OS line endings
With Classic Mac OS (pre-OS X), each line was terminated with a Carriage Return (decimal 13, hex 0D in ASCII). If a script file was saved with such line endings, Bash would only see one long line like so:
#!/bin/bash^M^Mcd "src"^Mnpm install^M^Mcd ..^M./tools/nwjs-sdk-v0.17.3-osx-x64/nwjs.app/Contents/MacOS/nwjs "src" &^M
Since this single long line begins with an octothorpe (#), Bash treats the line (and the whole file) as a single comment.
Note: In 2001, Apple launched Mac OS X which was based on the BSD-derived NeXTSTEP operating system. As a result, OS X also uses Unix-style LF-only line endings and since then, text files terminated with a CR have become extremely rare. Nevertheless, I think it’s worthwhile to show how Bash would attempt to interpret such files.
On JetBrains products (PyCharm, PHPStorm, IDEA, etc.), you'll need to click on CRLF/LF to toggle between the two types of line separators (\r\n and \n).
I was trying to startup my docker container from Windows and got this:
Bash script and /bin/bash^M: bad interpreter: No such file or directory
I was using git bash and the problem was about the git config, then I just did the steps below and it worked. It will configure Git to not convert line endings on checkout:
git config --global core.autocrlf input
delete your local repository
clone it again.
Many thanks to Jason Harmon in this link:
https://forums.docker.com/t/error-while-running-docker-code-in-powershell/34059/6
Before that, I tried this, that didn't works:
dos2unix scriptname.sh
sed -i -e 's/\r$//' scriptname.sh
sed -i -e 's/^M$//' scriptname.sh
If you're using the read command to read from a file (or pipe) that is (or might be) in DOS/Windows format, you can take advantage of the fact that read will trim whitespace from the beginning and ends of lines. If you tell it that carriage returns are whitespace (by adding them to the IFS variable), it'll trim them from the ends of lines.
In bash (or zsh or ksh), that means you'd replace this standard idiom:
IFS= read -r somevar # This will not trim CR
with this:
IFS=$'\r' read -r somevar # This *will* trim CR
(Note: the -r option isn't related to this, it's just usually a good idea to avoid mangling backslashes.)
If you're not using the IFS= prefix (e.g. because you want to split the data into fields), then you'd replace this:
read -r field1 field2 ... # This will not trim CR
with this:
IFS=$' \t\n\r' read -r field1 field2 ... # This *will* trim CR
If you're using a shell that doesn't support the $'...' quoting mode (e.g. dash, the default /bin/sh on some Linux distros), or your script even might be run with such a shell, then you need to get a little more complex:
cr="$(printf '\r')"
IFS="$cr" read -r somevar # Read trimming *only* CR
IFS="$IFS$cr" read -r field1 field2 ... # Read trimming CR and whitespace, and splitting fields
Note that normally, when you change IFS, you should put it back to normal as soon as possible to avoid weird side effects; but in all these cases, it's a prefix to the read command, so it only affects that one command and doesn't have to be reset afterward.
Coming from a duplicate, if the problem is that you have files whose names contain ^M at the end, you can rename them with
for f in *$'\r'; do
mv "$f" "${f%$'\r'}"
done
You properly want to fix whatever caused these files to have broken names in the first place (probably a script which created them should be dos2unixed and then rerun?) but sometimes this is not feasible.
The $'\r' syntax is Bash-specific; if you have a different shell, maybe you need to use some other notation. Perhaps see also Difference between sh and bash
Since VS Code is being used, we can see CRLF or LF in the bottom right depending on what's being used and if we click on it we can change between them (LF is being used in below example):
We can also use the "Change End of Line Sequence" command from the command pallet. Whatever's easier to remember since they're functionally the same.
One more way to get rid of the unwanted CR ('\r') character is to run the tr command, for example:
$ tr -d '\r' < dosScript.py > nixScript.py
I ran into this issue when I use git with WSL.
git has a feature where it changes the line-ending of files according to the OS you are using, on Windows it make sure the line endings are \r\n which is not compatible with Linux which uses only \n.
You can resolve this problem by adding a file name .gitattributes to your git root directory and add lines as following:
config/* text eol=lf
run.sh text eol=lf
In this example all files inside config directory will have only line-feed line ending and run.sh file as well.
For Notepad++ users, this can be solved by:
The simplest way on MAC / Linux - create a file using 'touch' command, open this file with VI or VIM editor, paste your code and save. This would automatically remove the windows characters.
If you are using a text editor like BBEdit you can do it at the status bar. There is a selection where you can switch.
For IntelliJ users, here is the solution for writing Linux script.
Use LF - Unix and masOS (\n)
Scripts may call each other.
An even better magic solution is to convert all scripts in the folder/subfolders:
find . -name "*.sh" -exec sed -i -e 's/\r$//' {} +
You can use dos2unix too but many servers do not have it installed by default.
For the sake of completeness, I'll point out another solution which can solve this problem permanently without the need to run dos2unix all the time:
sudo ln -s /bin/bash `printf 'bash\r'`
I'm trying to enable malloc debug for my android application, and for the life of me i can't get it working.
My wrap.sh scripts each contain this:
#!/system/bin/sh
LIBC_DEBUG_MALLOC_OPTIONS="free-track verbose"
logwrapper "$#"
and I've set up the following directory structure:
When I grep logcat for "malloc debug enabled", I get nothing.
If i change my wrap.sh scripts contents to this
#!/system/bin/sh
LIBC_DEBUG_MALLOC_OPTIONS=free-track logwrapper "$#"
which is exactly what the documentation for the wrap shell script says to add (although to me that seems like invalid shell script syntax), i can see the "malloc debug enabled" log message, but my application freezes at the splash screen and never actually launches.
I'm not sure what's going on and would love any type of input.
Other notes:
My project is using CMake.
My debug device is running Android P.
That is for running an executable binary on Android. I think you are running a Java app with JNI calls, and that trick does not apply to you. You will have to set those environment variables from JAVA as the app starts.
Try looking at OS.setenv() - https://developer.android.com/reference/android/system/Os.html. I hope that those environment variables can be set from Java before the JNI library is loaded, or that the library reads those environment variables on every call, and not just init.
If the accepted answer doesn't work for you then my solution might work:
#!/system/bin/sh
LIBC_DEBUG_MALLOC_OPTIONS=free-track logwrapper
exec "$#"
Make sure line endings are LF and not CRLF.
Then my issue was that malloc debug wasn't able to write the dump:
E/malloc_debug: Unable to create file: /data/local/tmp/backtrace_heap.16934.exit.txt
I thought this might be due missing permissions. By changing the output folder to the one of your app, this is circumvented:
LIBC_DEBUG_MALLOC_OPTIONS='backtrace backtrace_dump_on_exit backtrace_dump_prefix=data/data/com.your.app/files/dump' logwrapper
And dumping now works:
E/malloc_debug: Dumping to file: data/data/com.your.app/files/dump.17599.exit.txt
Also make sure you set
buildTypes{
debug {
debuggable true
}
}
in build.gradle and
android:extractNativeLibs="true"
android:debuggable="true"
in the AndroidManifest.xml file
I am trying to add a strip debug symbols step for my Android library which includes native shared libraries for different ABIs, e.g. x86/native-lib.so, x86_64/native-lib.so, arm64-v8a/native-lib.so, etc.
I understand that the strip command must be respective to each ABI. So, I need to invoke the correct strip command, for which I need to know its correct path during build time.
For example, for ABI x86_64, I need to have below path setting:
set(STRIP ~/Library/Android/android-ndk-r16b/toolchains/x86_64-4.9/prebuilt/darwin-x86_64/bin/x86_64-linux-android-strip)
add_custom_command(TARGET ${SHARED_LIBRARY_NAME} POST_BUILD
COMMAND ${STRIP}
"${DIST_LIBS_DIR}/${LIB_BUILD_TYPE}/${ANDROID_ABI}/lib${SHARED_LIBRARY_NAME}.so"
COMMENT "Strip debug symbols done on final binary.")
The path I need is illustrated like below:
So, my questions are:
Is there an existing CMake variable to point at this path, i.e. /android-ndk-r16b/toolchains/???/prebuilt/???/bin/???-???-???-strip?
If not, is there a way to form this path utilising other known Android CMake variable, e.g. ANDROID_NDK, ANDROID_ABI, etc?
Thanks #Alex Cohn a lot for pointing out the file android.toolchain.cmake which usually exists at directory ~/Library/Android/sdk/cmake/cmake_version_xxx/android.toolchain.cmake on macOS.
There are many useful Android CMake variables already configured inside, e.g.
ANDROID_NDK
ANDROID_TOOLCHAIN
ANDROID_ABI
ANDROID_PLATFORM
ANDROID_STL
ANDROID_PIE
ANDROID_CPP_FEATURES
ANDROID_ALLOW_UNDEFINED_SYMBOLS
ANDROID_ARM_MODE
ANDROID_ARM_NEON
ANDROID_DISABLE_NO_EXECUTE
ANDROID_DISABLE_RELRO
ANDROID_DISABLE_FORMAT_STRING_CHECKS
ANDROID_CCACHE
And the one ANDROID_TOOLCHAIN_PREFIX is exactly what I looked for, so my final CMake script comes into below:
add_custom_command(TARGET ${SHARED_LIBRARY_NAME} POST_BUILD
COMMAND "${ANDROID_TOOLCHAIN_PREFIX}strip" -g -S -d --strip-debug --verbose
"${DIST_LIBS_DIR}/${LIB_BUILD_TYPE}/${ANDROID_ABI}/lib${SHARED_LIBRARY_NAME}.so"
COMMENT "Strip debug symbols done on final binary.")
And I don't need to explicitly pass any additional arguments, i.e. DCMAKE_TOOLCHAIN_FILE=android.toolchain.cmake, from command line to the build process. Because, this file, i.e. android.toolchain.cmake, was already taken into account automatically by Android native build system.
You can use ${CMAKE_STRIP}. It is set appropriately when you use -DCMAKE_TOOLCHAIN_FILE=android.toolchain.cmake. I hope it is OK also if you work with 'built-in' Android support with supported NDK version.
I would like to use the apitrace project on android. I followed the instructions from the readme file.
But get no trace where created.
I run this command
adb shell TRACE_FILE=/data/test.trace LD_PRELOAD=/data/egltrace.so am start -n APP_NAME
How can I make it work?
I tried following the instructions in Dalvik.markdown of the original distribution of apitrace, but without success.
The instructions say to set two properties: wrap._process_name_ and debug.apitrace.procname. The former has to be set, according to those instructions, to LD_PRELOAD=/data/egltrace.so. When launching the application I still wouldn't get any trace generated nor any apitrace-related message in the logcat.
I had more success by putting the LD_PRELOAD instruction in a script and using that as the wrapper. This is the script that I use, called /data/apitrace.sh:
LD_PRELOAD=/data/egltrace.so exec $#
You can also set the TRACE_FILE environment variable to specify the path to which the trace file should be written to. Otherwise it will be _/data/app_process.trace_. For example:
TRACE_FILE=/data/apitraces/mytrace.trace LD_PRELOAD=/data/egltrace.so exec $#
I believe apitrace takes care of adding numbers to the filename to prevent overwriting existing ones. So you'll have mytrace.trace, mytrace.1.trace, and so on.
So with this script in place I set the properties like so:
adb shell setprop wrap._process_name_ /data/apitrace.sh
adb shell setprop debug.apitrace.procname _process_name_
And then I launch the application. I see in the logcat something like the following:
I/dalvikvm( 5980): Exec: /system/bin/sh -c /data/apitrace.sh /system/bin/app_process /system/bin --application '--nice-name=_process_name_' com.android.internal.os.WrapperInit 25 17 'android.app.ActivityThread'
D/apitrace( 5991): apitrace: loaded
D/apitrace( 5991): apitrace[5991]: enabled for _process_name_
D/apitrace( 5991): apitrace: tracing to /data/app_process.trace
I'm using CyanogenMod 10.1.3, which is based on Android 4.2.2.
I was wondering if there is any way to access the logcat logging data from native code ?
Also if someone knows what kind of shell can be accessed on the native linux system directly on the device itself (so NOT by starting a shell through adb on a client pc !!!) ?
Thanks in advance
You can either read the raw data fom /dev/log/main or you can run the built-in shell command logcat and pipe the result to a file descriptor as usual. The logcat command is usually preferably because then the printout is easier to filter and format.
As for the built-in shell, it is called toolbox and the source can be found in the Android open source project. The shell is rather similar to bash. Toolbox contains lots more functionality than just a shell. It is very similar to Busybox, but released under another license.
You can set it up using a log tag in your source file and then include the library as so:
#define LOG_TAG "some.unique.identifier" //I usually use the class name
#include <utils/Log.h>
Then in the Android.mk file you will need to add the liblog library dependency to your LOCAL_SHARED_LIBRARIES.
LOCAL_SHARED_LIBRARIES += liblog
Also, take note that logcat looks for the LOG_TAG definition to include as part of the tagging so it makes searching for your logs easier. Then you can log as such:
int my_int = 0;
ALOGI("some logs.... print my int: %d", my_int);
ALOGI is for info, you can also use ALOGE, ALOGD, ALOGV and ALOGW for error, debug, verbose and warning logging, respectively.
ALOG* is analogous to printf. I interchange them at times if I need to debug on different platforms, say Linux.