So I wrote a program to run on a Tp-link device running OpenWrt Attitude Adjustment 12.09.
I wrote the makefiles successfully in the /OpenWrt-SDK../package/myprogram/src/Makefile and it all ran smoothly when I did a 'make'.
Now I added threads in my program so I configured the Makefile like this:
# build myprogram executable when user executes "make"
LDFLAGS=-pthread
myprogram: myprogram.o
$(CC) $(LDFLAGS) myprogram.o -o myprogram
myprogram.o: myprogram.c
$(CC) $(CFLAGS) -c myprogram.c
# remove object files and executable when user executes "make clean"
clean:
rm *.o myprogram
and when I 'make' inside the package/myprogram/src folder it compiles successfully and runs just fine on my PC.
Now when I go to the root OpenWrt-SDK directory to 'make' I get a missing dependencies error:
Package myprogram is missing dependencies for the following libraries:
libpthread.so.0
So what do I need to do to include these dependencies?
I went to my OpenWrt-SDK root and tried:
./scripts/feeds search libpthread
And I got this result:
./scripts/feeds search libpthread
Search results in feed 'trunk':
libpthread POSIX thread library
Should I install that or is that not it? I do not know if I am doing something else wrong.
I will appreciate any help! Thanks.
Under package definition add
DEPENDS:=+libpthread
Related
I am trying to compile a simple makefile program in C using Clion. I have the most up to date version of Clion and have reinstalled Cygwin and the suggested plugins as referenced by https://www.jetbrains.com/help/clion/quick-tutorial-on-configuring-clion-on-windows.html#Cygwin
However, I keep getting this error:
Error message
"CreateProcess error=2, The system cannot find the file specified
Cannot run program "make" (in directory "C:\College\Fall2020\COMS 327\coms327p1"): CreateProcess error=2, The system cannot find the file specified:
CreateProcess error=2, The system cannot find the file specified"
At first I figured it was just an issue with my make file, however I transferred this project over to linux and ran it from the command line and it works perfectly. So I am not sure why I cannot get this makefile project to run on windows.
For reference I am including my makefile as well:
all: gensine gendial
gensine: main.c
gcc -o gensine main.c -lm
gendial: main2.c
gcc -o gendial main2.c -lm
clean:
rm gensine gendial
I am building a Swift command-line application with references to a third party library (netcdf) in /usr/local/lib. I have a bridging header in the project and when making the appropriate calls, there are no errors. So I'm fairly confident that the #include is being found in the bridging file.
In Build Settings, I have added /usr/local/lib to Library Search Paths and -lnetcdf to Other Linker Flags.
However I am seeing a link failure. Specifically I am seeing an undefined symbols message. Looking at the ld command shown when I click on the error, I can see that -L/usr/local/lib is there. However the -lnetcdf is not.
What else do I have to do to get the -l into the link command?
After three hours of trying to resolve this, I eventually thought 'stuff it' and spent about 15 mins writing a Makefile.
CLIBS=-lnetcdf
SWFILES=main.swift NCUtil.swift
SWIMPORT=-import-objc-header ../GSIP-Bridging-Header.h
SWIFTLIB=/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/macosx
SLIBS=-lSystem -lobjc
GSIP: main.o NCUtil.o
ld $^ -arch x86_64 -L $(SWIFTLIB) $(SLIBS) $(CLIBS) -rpath $(SWIFTLIB) -macosx_version_min 10.10 -no_objc_category_merging -o $#
%.o: %.swift
swiftc -c $(SWFILES) -target x86_64-apple-darwin14.5.0 -I /usr/local/include -I /usr/include $(SWIMPORT) -module-name=GSIP
.PHONY: clean
clean:
rm -f *.o GSIP
There is in fact another solution. Using the Finder menu to Go -> Go to Folder, go to the directory where the dylib is located. Then from Finder, drop and drag the dylib into your project. Probably a wise idea to use a reference rather than make a copy of the file.
This resolved all my link errors!
first off, this is a programming assignment so you are aware.
Anyhow, what I am trying to do is include a shared library I wrote (a linked list from a previous project) in with my own shell I am writing. The issue I incur is that when I compile using my Makfile, the compile is successful. Then when I try to run my executable (let's say it's called prog), I get the following:
[terminal]# ./prog
./prog: error while loading shared libraries: libmylib.so: cannot open shared object file: No such file or directory
The following is my file structure for reference:
include
|_
common.h
List.h
Node.h
lib
|_
libmylib.a
libmylib.so
libsrc
|_
Makefile // This makefile builds the library correctly and puts it in lib via 'make install'
List.c
List.h
Node.c
Node.h
common.h
Makefile
prog.c
Here is my main Makefile
CC=gcc
CFLAGS=-g -Wall -Llib
LIBS=-lreadline -lncurses -lmylib
PROGS=library prog
all: $(PROGS)
library:
cd libsrc; make install
prog: prog.o
$(CC) $(CFLAGS) -o $# $< $(LIBS)
clean:
cd libsrc; make installclean
/bin/rm -f *.o $(PROGS) a.out core *.log
Any help or advice is appreciated, thanks!
The runtime dynamic linker does not know where to find your shared library.
Two options:
Set the LD_LIBRARY_PATH environment variable to include the absolute path to your lib directory:
LD_LIBRARY_PATH=/path/to/lib
export LD_LIBRARY_PATH
Hard-code the absolute path to your lib directory in the executable image by passing -R/path/to/lib to the linker (e.g. in your makefile, CFLAGS=... -Llib -R/path/to/lib.
The first option is flexible, in the sense that the shared library can be installed anywhere and even moved to another location, and the executable won't break as long as the environment variable is updated accordingly. But it does require the user (or system administrator) must set up the environment correctly.
The second option does not allow the shared library to be moved from its predefined installation directory, but removes the dependencies on a correctly setup environment.
Note that you won't need to do either if you install your shared library in a standard system-specific location (e.g. /usr/lib or /usr/lib64 on Unix/Linux) as the runtime linker will search such locations automatically.
I need to obtain the information on the C-compiler used to build an installed program. I am guessing a rt or a lib can report that, but nothing concrete. Not that the program would be installed in /usr/... or a similar place, and hence would not have access to the build directory to get the relevant info.
Well behaved programs should understand the --version argument.
Packaged programs (i.e. those installed with dpkg -i or apt-get install of a .deb package on Debian, etc...) also know their package version and source.
You might try to use strings on the binary executable. However, such meta-data (about the version of the C compiler used to build the program) might have been stripped (e.g. by the strip command).
If you are developing the program (i.e. its C source code) and can change it, you might consider adding something like
timestamp.c: Makefile
echo 'const char timestamp[]=' > $#
date +'"built with $(shell $(CC) --version) on %c";' >> $#
yourprogram: $(OBJECTS) timestamp.o
$(LINK.c) $(LDFLAGS) $< -o $# $(LDLIBES)
$(RM) timestamp.c
in your Makefile (details could be wrong, but you get the idea)
I've made a C program that uses libsndfile to extract some data from audio files.
What possibilities are there to make the program as portable as possible, preferably without requiring root access when installing?
Libsndfile is not available at the target machines, so i need to somehow package it with my program. Is there a way to statically link the library? I've also looked at some Autotools tutorials, but I'm not sure how to proceed.
I can compile without a hitch on my dev machine, where I installed the libraries using the package manager: apt-get install libsnfile1-dev
The makefile is very simple:
CFLAGS=-std=c99 -Wall -pedantic -g
CLIBS= -lsndfile -lm
BIN=audiodecode
CC=gcc
MAIN=main.o
FILES=
OBJS=$(FILES) $(MAIN)
.PHONY: all
all: clean $(OBJS)
$(CC) $(CFLAGS) -o $(BIN) $(OBJS) $(CLIBS)
.PHONY: clean
clean:
rm -f *.o $(BIN)
A lot of packages bundle their dependencies. Examples: rsync (contains a bundled libpopt), gnupg (contains a bundled libz). Other dependencies commonly bundled are gettext or glib.
For inspiration look at how these popular open source projects do it.
Put the content of http://www.mega-nerd.com/libsndfile/files/libsndfile-1.0.25.tar.gz into a subdir and add apropriate rules to build the the subdir first.
Untested sample code:
OBJS += libsndfile/libsndfile.a
libsndfile/libsndfile.a:
cd libsdndfile && ./configure --enable-static && $(MAKE)
For Bonus points add a configure script, that check if the system has already installed libsndfile and link to it dynamically.