I have a project for college, where i need to use libjpeg (C language), to complete 2 codes the teacher gave to us. It's a about transforming a pic into ASCII symbols (like the ASCII draws, you know)
We have a code for reading a jpg and a code for writing a jpg.
The problem is i had to install the libjpeg, i THINK the installation went well but i'm not sure so i have 2 questions
How can i verify libjpeg is correctly installed ? i didn't link it to gcc so i have to use the option for saying to gcc where is jpeg-6b (the folder which contains ljpeg) so i tried this :
Typing "gcc -L/jpeg-6b" the folder is jpeg-6b and it's right on the location where i do the command. i only get an error message about the fact the input is empty (normal ok), i think if the lib was not correctly installed, i should get an error for saying me i can't use the libjpeg version, right ?
In the 2 codes i said the teacher gave to us, she puts #include <libjpeg> on the beginning of it. But i saw on the internet that people use #include <jpeglib.h>, but both of them DON'T work and i get a message telling me :
test.c:1:21: fatal error: jpeglib.h: no such file or directory
#include <jpeglib.h>
is my include bad? or is the libjpeg bad installed ? (i read the doc and i did ./configure then make like it's said)
Just as you add -L/jpeg-6b you need -I/jpeg-6b/path/to/jpeg/headers too. I would recommend a Makefile to automate this.
Related
I just started trying to program in C and I've downloaded all kinds of IDE's and compilers and nothing seems to be working. Cygwin keeps giving me this error when i try to compile my program:
C:\Users\Paul\Documents\Timmy
λ gcc -o nutt nutt.c
/usr/lib/gcc/x86_64-pc-cygwin/6.4.0/../../../../x86_64-pc-cygwin/bin/ld:
cannot open output file nutt.exe: No such file or directory
collect2: error: ld returned 1 exit status.
here is my program
#include <stdio.h>
int main(void) {
printf("y");
return 0;
}
I also want to point out that i have this strange issue when i try to use the "save as" features in notepad or notepad++. when i try to save something this way it will bring up an error message saying the file isn't found and to check the file name and try again. both of these issues seem to have occured around the same time, i'm not sure if they are related. I try saving this way by setting the file type to all types and i just type in "something.c" for the name.
I fixed it! thank you guys for trying to help. I fixed it by turning off controlled folder access in my windows defender security center.
https://answers.microsoft.com/en-us/windows/forum/windows_10-files/cant-save-to-documents-folder-after-fall-creators/b1274473-6dcd-4bbf-8040-6ba1bc79287f
I can now use the save as features and compile my C source files.
I kept trying to google stuff about gcc when it was really window's fault...
I am trying to compile some source codes about UNIX scokets programs, on Linux I have no problems but on macOS I get stuck in front of types definition problems. I don't know how many details I can put here, but I'll try.
The source codes to be compiled are:
errlib.c
errlib.h
server_test.c
sockwrap.c
sockwrap.h
where the main is located in server_test.c.
To compile I use:
gcc -Wall -DTRACE -o server_test server_test.c errlib.c sockwrap.c
There are no problems running this on Linux, but on macOS I get more than 20 error and all of these are about a (perhaphs) missing definition of bool_t. I suppose something not working in /usr/include/rpc/* files located in macOS internal libraries.
So I looked for if <sys/types.h> is included in /usr/include/rpc/xdr.h and it seems to be not missing.
Some of the first lines of the gcc output are:
In file included from server_test.c:16:
/usr/include/rpc/xdr.h:126:3: error: type name requires a specifier or qualifier
bool_t (*x_getlong)(struct __rpc_xdr *, int *);
^
/usr/include/rpc/xdr.h:126:10: error: function cannot return function type 'int (struct __rpc_xdr *, int *)'
bool_t (*x_getlong)(struct __rpc_xdr *, int *);
^
/usr/include/rpc/xdr.h:128:3: error: type name requires a specifier or qualifier
bool_t (*x_putlong)(struct __rpc_xdr *, const int *);
^
/usr/include/rpc/xdr.h:128:10: error: function cannot return function type 'int (struct __rpc_xdr *, const int *)'
bool_t (*x_putlong)(struct __rpc_xdr *, const int *);
^
/usr/include/rpc/xdr.h:128:3: error: duplicate member 'bool_t'
bool_t (*x_putlong)(struct __rpc_xdr *, const int *);
^
/usr/include/rpc/xdr.h:126:3: note: previous declaration is here
bool_t (*x_getlong)(struct __rpc_xdr *, int *);
^
/usr/include/rpc/xdr.h:136:3: error: type name requires a specifier or qualifier
bool_t (*x_getbytes)(struct __rpc_xdr *, char *, unsigned int);
...
and many others lines that are very similar.
For those who want to deepen, the sources are available here.
What could be the problem?
The bad answer
Issue solved by simply including <rpc/types.h> in the server_test.c source as follows:
#include <rpc/types.h>
The better one
This is a solution above is valid only for this server_test.c implementation.
If you want fix this issue "globally", you can follow follown steps:
disable SIP (how to? here)
get your macOS's xdr.h (from here /usr/include/rpc/xdr.h)
copy it elsewhere two times: one copy is for backup and modify the other one simply adding the required include (#include <rpc/types.h> and see the picture below)
overwrite your modified xdr.h onto the original one in /usr/include/rpc/
re-enable SIP
Here is how I did it:
I'm fairly new to programming with c and i am having a hard time including the squash library into my program.
I cloned the repository and ran ./configure and make sudo make install.
That installed the files:
/usr/local/lib/pkgconfig/squash-0.8.pc
/usr/local/lib/libsquash0.8.so.0.8
/usr/local/lib/libsquash0.8.so.0.8.0
/usr/local/lib/libsquash0.8.so
/usr/local/lib/cmake/Squash-0.8.0/SquashConfig.cmake
/usr/local/bin/squash
And some more files in this directories:
/usr/local/include/squash-0.8/
/usr/local/lib/squash/0.8/plugins/
In the squash examples the library is included by #include <squash/squash.h> but when i am trying to compile it i get fatal error: squash/squash.h: No such file or directory
Also #include <squash-0.8/squash.h> doesnt work because then i get fatal error: hedley/hedley.h: No such file or directory That file is located at
/usr/local/include/squash-0.8/squash/hedley/hedley.h
I guess the solution is pretty simple for an experienced c programmer but i am failing here..
Do i need to set some sort of environment variable to let the compiler find the library?
And how do i link the library to the compiler anyway?
I found something like:
-rdynamic ../squash/libsquash0.8.so.0.8 but could not test it yet because of the error above.
Try to change
#include <squash/squash.h>
to
#include "squash/hedley/hedley.h"
or
#include "<squash-0.8/squash/hedley/hedley.h>"
easier and faster solution would be adding the path to your includes during compilation:
-I/usr/local/include/squash-0.8/squash/
I'm trying to use YCM for the first time so in order to make it work I decided to give a chance for the YCM-Generator, which generates the .ycm_extra_conf.py file automatically based on the makefile.
So far my program is just a simple hello world.
#include <stdio.h>
int main()
{
printf("Hello World!");
return 0;
}
I'm using the CMakeLists.txt trick to generate the makefile.
file(GLOB sources *.h *.c)
add_executable(Foo ${sources})
then after executing the YCM-Generator script, I get this output
Running cmake in '/tmp/tmp_YknVy'... $ cmake
/home/pedro/Desktop/Projetos/teste
Running make... $ make -i -j4
Cleaning up...
Build completed in 1.5 sec
Collected 2 relevant entries for C compilation (0 discarded).
Collected 0 relevant entries for C++ compilation (0 discarded).
Created YCM config file with 0 C flags
YCM plugin does find the .ycm_extra_conf.py file, but the auto-completion doesn't work right, for example, if I type "floa", it doesn't suggests "float", but It only suggests things that I used before like "int" or "printf".
Am I missing something or this is working as intended?
So I fixed it.
For c it does require a .ycm_extra_conf.py , while a friend of mine could make it work without one in c++.
The auto complete only suggest automatically functions that were previously used, if you don't remember a function name you have to press <Ctrl-Space>
YCM-Generator didn't do the job, so I modified the example file myself following the comments.
If you are used to Visual Assist, the auto complete works but it's really weak if compared to VA, which is a shame... I really hope someone port that plugin to Linux.
I am working on a project which requires me to download and use this. Inside the downloaded folder, when extracted I am presented with three things:
A folder called "include"
A folder called "src"
A file called "Makefile"
After some research, I found out that I have to navigate to the directory which contains these files, and just type in the command make.
It seemed to install the library in my system. So I tried a sample bit of code which should use the library:
csp_conn_t * conn;
csp_packet_t * packet;
csp_socket_t * socket = csp_socket(0);
csp_bind(socket, PORT_4);
csp_listen(socket, MAX_CONNS_IN_Q);
while(1) {
conn = csp_accept(socket, TIMEOUT_MAX);
packet = csp_read(conn, TIMEOUT_NONE);
printf(“%S\r\n”, packet->data);
csp_buffer_free(packet);
csp_close(conn);
}
That's all that was given for the sample server end of the code. So I decided to add these to the top:
#include <csp.h>
#include <csp_buffer.h>
#include <csp_config.h>
#include <csp_endian.h>
#include <csp_interface.h>
#include <csp_platorm.h>
Thinking I was on the right track, I tried to compile the code with gcc, but I was given this error:
csptest_server.c:1: fatal error: csp.h: No such file or directory
compilation terminated.
I thought I may not have installed the library correctly after all, but to make sure, I found out I could check by running this command, and getting this result:
find /usr -iname csp.h
/usr/src/linux-headers-2.6.35-28-generic/include/config/snd/sb16/csp.h
/usr/src/linux-headers-2.6.35-22-generic/include/config/snd/sb16/csp.h
So it seems like the csp.h is installed, maybe I am referencing it incorrectly in the header include line? Any insight? Thanks a lot.
The make command is probably only building the library, but not installing it. You could try sudo make install. This is the "common" method, but I recommend you to check the library's documentation, if any.
The sudo command is only necessary if you have no permissions to write the system's include and library directories, which may be your case.
Another possibility (instead of installing the library) is telling GCC the location of the library's source code and generated binaries (by means of the -I and -L options of the gcc command.
That Makefile will not install anything, just translate the source into a binary format.
The csp.h in the Linux kernel has nothing to do with your project, it's just a naming collision, likely to happen with three letter names.
In your case, I would presume you need to add the include directory to the compilation flags for your server, like gcc -I/path/to/csp/include/csp csptest_server.c.
(Next, you'll run into linker errors because you'll also want to specify -L/path/to/csp -lcsp so that the linker can find the binary code to link to.)