I'm trying to code to refresh my memory preparing myself for a course.
int main(){
int x;
for( x = 0;x < 10; x++){
printf("Hello world\n");
}
return 0;
}
But when I tried to run this I get Too few arguments
I compiled the code above using gcc -o repeat file.c Then to run this I just type repeat
Sorry if this was a stupid question, it has been a while since I took the introduction class.
When you type
filename
at a prompt, your OS searches the path. By default, Linux doesn't include the current directory in the path, so you end up running something like /bin/filename, which complains because it wants arguments. To find out what file you actually ran, try
which filename
To run the filename file gcc created in the working directory, use
./filename
Your code compiles fine. Try:
gcc -o helloworld file.c
./helloworld
UPDATE :
Based on more recent comments, the problem is that the executable is named repeat, and you're using csh or tcsh, so repeat is a built-in command.
Type ./repeat rather than repeat.
And when asking questions, don't omit details like that; copy-and-paste your source code, any commands you typed, and any messages you received.
The executable is named file, which is also a command.
To run your own program, type
./file
EDIT :
The above was an educated guess, based on the assumption that:
The actual compilation command was gcc file.c -o file or gcc -o file file.c; and
The predefined file command (man file for information) would produce that error message if you invoke it without arguments.
The question originally said that the compilation command was gcc file.c; now it says gcc -o filename file.c. (And the file command prints a different error message if you run it without arguments).
The correct way to do this is:
gcc file.c -o filename && ./filename
(I'd usually call the executable file to match the name of the source file, but you can do it either way.)
The gcc command, if it succeeds, gives you an executable file in your current directory named filename. The && says to execute the second command only if the first one succeeds (no point in trying to run your program if it didn't compile). ./filename explicitly says to run the filename executable that's in the current directory (.); otherwise it will search your $PATH for it.
If you get an error message Too few arguments, it's not coming from your program; you won't see that message unless something prints it explicitly. The explanation must be that you're running some other program. Perhaps there's already a command on your system called filename.
So try doing this:
gcc file.c -o filename && ./filename
and see what happens; it should run your program. If that works, try typing just
filename
and see what that does. If that doesn't run your program, then type
type -a filename
or
which filename
to see what you're actually executing.
And just to avoid situations like this, cultivate the habit of using ./whatever to execute a program in the current directory.
Related
Hello I am learning c and I have created a simple script. I ran it with gcc simplify.c -o simplify.
Here is the c script
#include<stdio.h>
int main(){
int age = 3;
printf("%i\n", age);
return 0;
}
when I try to run it
$simplify.exe
bash: run: command not found
I get the result shown. What am I doing wrong
Whenever you use a filename as a command, bash will search for it in directorys like /usr/bin. Imagine the situation, in which someone put a executable called ls somewhere unprotected on your computer. Like #some programmer dude pointed out, you habe to explicitly specify the path to your executable. This path can be relative (./simplify.exe) or absolute (/home/username/projects/simplify/simplify.exe).
By the way, on linux systems it is umcommon to use a file ending, espacially ".exe". If you want to use one, I recommend ".elf", which stands for "executable linkable file". (You can do so much more than EXEcuting a file - and down we go the rabbit hole)
$ rustc <(echo 'fn main(){ print!("Hello world!");}')
$ ls
63
$ gcc <(echo '#include<stdio.h> int main(){ printf("Hello world!\n"); return 0;}')
/dev/fd/63: file not recognized: Illegal seek
collect2: error: ld returned 1 exit status
Why can't ld link the program?
The gcc command is mostly a dispatch engine. For each input file, it determines what sort of file it is from the filename's extension, and then passes the file on to an appropriate processor. So .c files are compiled by the C compiler, .h files are assembled into precompiled headers, .go files are sent to the cgo compiler, and so on.
If the filename has no extension or the extension is not recognised, gcc assumes that it is some kind of object file which should participate in the final link step. These files are passed to the collect2 utility, which then invokes ld, possibly twice. This will be the case with process substitution, which produces filenames like /dev/fd/63, which do not include extensions.
ld does not rely on the filename to identify the object file format. It is generally built with several different object file recognisers, each of which depends on some kind of "magic number" (that is, a special pattern at or near the beginning of the file). It calls these recognisers one at a time until it finds one which is happy to interpret the file. If the file is not recognised as a binary format, ld assumes that it is a linker script (which is a plain text file) and attempts to parse it as such.
Naturally, between attempts ld needs to rewind the file, and since process substitution arranges for a pipe to be passed instead of a file, the seek will fail. (The same thing would happen if you attempted to pass the file through redirection of stdin to a pipe, which you can do: gcc will process stdin as a file if you specify - as a filename. But it insists that you tell it what kind of file it is. See below.)
Since ld can't rewind the file, it will fail after the file doesn't match its first guess. Hence the error message from ld, which is a bit misleading since you might think that the file has already been compiled and the subsequent failure was in the link step. That's not the case; because the filename had no extension, gcc skipped directly to the link phase and almost immediately failed.
In the case of process substitution, pipes, stdin, and badly-named files, you can still manually tell gcc what the file is. You do that with the -x option, which is documented in the GCC manual section on options controlling the kind of output (although in this case, the option actually controls the kind of input).
There are a number of answers to questions like this floating around the Internet, including various answers here on StackOverflow, which claim that GCC attempts to detect the language of input files. It does not do that, and it never has. (And I doubt that it ever will, since some of the languages it compiles are sufficiently similar to each other that accurate detection would be impossible.) The only component which does automatic detection is ld, and it only does that once GCC has irrevocably decided to treat the input file as an object file or linker script.
At least in your case, you can use process substition when specifying the input language manually, using -xc. However, you should put a newline after the include statement.
$ gcc -xc <(echo '#include<stdio.h>
int main(){ printf("Hello world!\n"); return 0;}')
$ ls
a.out
$ ./a.out
Hello world!
For a possible reason why this works, see Charles' answer and the comments on this answer.
I'm using GCC version 4.7.1, but I've also tried this on GCC 4.8. Here is the code I'm trying to compile:
#include <stdio.h>
void print(int amount) {
int i;
for (i = 0; i < 5; i++) {
printf("%d", i);
}
}
int main(int argc, char** argv) {
print(5);
return 0;
}
It looks like it should work, and when I compile with...
gcc main.c
It takes a while to compile, produces an a.exe file and the the a.exe file disappears. It isn't giving me any errors with my code.
Here's a gif of proof, as some people are misinterpreting this:
(Since ahoffer's deleted answer isn't quite correct, I'll post this, based on information in the comments.)
On Windows, gcc generates an executable named a.exe by default. (On UNIX-like systems, the default name, for historical reasons, is a.out.) Normally you'd specify a name using the -o option.
Apparently the generated a.exe file generates a false positive match in your antivirus software, so the file is automatically deleted shortly after it's created. I see you've already contacted the developers of Avast about this false positive.
Note that antivirus programs typically check the contents of a file, not its name, so generating the file with a name other than a.exe won't help. Making some changes to the program might change the contents of the executable enough to avoid the problem, though.
You might try compiling a simple "hello, world" program to see if the same thing happens.
Thanks to Chrono Kitsune for linking to this relevant Mingw-users discussion in a comment.
This is not relevant to your problem, but you should print a newline ('\n') at the end of your program's output. It probably doesn't matter much in your Windows environment, but in general a program's standard output should (almost) always have a newline character at the end of its last line.
Try to compile with gcc but without all standard libraries using a command like this:
gcc -nostdlib -c test.c -o test.o; gcc test.o -lgcc -o test.exe
One of the mingw libraries binary must generate a false positive, knowing which library would be useful.
There is no issue with your code it is just exiting properly.
You have to run it in the command line which will show you all the info.
start->run->cmd, then cd to your directory. then a.exe. If you don't want to do that you can add a sleep() before the return in main.
More over, in your code when you pass print(5) to your function it's not being used.
I confirm is due to Antivirus.
I did this test:
compile helloworld.c at t=0;
within 1 second tell McAfee not consider helloworld.exe a threat. >> the file is still there
If I am too slow, the file will be deleted.
If suppose you get the error near a.exe while running the file ,
Theen follow the below steps:
1.open virus & threat protection
2.there select manage settings in virus & threat protection settings
3.there is real time protection and cloud delivered protection is in ON then OFF the real time protection and cloud delivered protection.!
(https://i.stack.imgur.com/mcIio.jpg)
a.exe is also the name of a virus. I suspect your computer's security software is deleting or quarantining the file because it believes it is a virus. Use redFIVE's suggestion to rename your output file to "print.exe" so that the virus scanner does not delete it.
You try:
gcc -o YOUR_PROGRAM.exe main.c
You can stop your antivirus software from deleting your .exe by specifying the full file path (for eg: c:\MyProject) in the 'paths to be excluded from scanning' section of the antivirus software.
Hello everyone I'm learning C and am trying to figure out how to run it through the command console cmd. I have eclipse installed along with Mingw and added these to the path:
C:\MinGW\bin\;C:\MinGW\msys\1.0\bin
I wrote this program on notepad++ for a quick test run and save it to C:\test.c and also under a folder C:\Users\Pikachu\Music\C code while I was trying to figure it out:
#include <stdio.h>
int main()
{
printf("Hey, Buddy!\n");
return 0;
}
On the cmd console I typed:
c:\>gcc test.c
and got the error message:
c:/mingw/bin/../lib/gcc/mingw32/4.8.1/../../../../mingw32/bin/id.exe: cannot ope
n output file a.exe: Invalid argument
collect2.exe: error: ld returned 1 exit status
When I typed:
c:\>cd c:\Users\Pikachu\Music\c code
and then:
gcc test.c
it just skipped a line as if nothing happened and went back to square one:
c:\Users\Pikachu\Music\c code>gcc test.c
c:\Users\Pikachu\Music\c code>
I was wondering if anyone knows what's going on and could help me out, I'd be so happy if I could see "Hey, Buddy" from cmd! Does anyone also know why I get the error message running it from c:\ and nothing when I run it from the Music\c code\test.c folder even though I'm supposedly running the same file test.c?
I've tried searching around and have picked up references on how the computer can't link to the proper dll's however I'm not sure how to implement this to my specific problem.
Oh and curiously enough when I tried to save another file in c:\ I got a message saying that I didn't have permission to do that even though 5 minutes prior I had done just this. Any insights?
Thanks for your help!
When you run gcc on your C source file, all that it will do it generate an executable file. I believe its called a.exe by default but I would recommend naming it with the -o option:
gcc text.c -o test.exe
Once your file is successfully compiled, run the executable to say hello to the worls:
c:\Users\Pikachu\Music\c code> .\test.exe
As for the first error you got, maybe it has to do with gcc not being able to create the output executable on the root c: folder. I would recommend doing your coding some folder your user owns instead of on a system folder for this reason.
By the way, gcc supports many other options. I highly recommend using -Wall to turn on warnings and choosing what version of the C standard to follow (-std=c99 or -ansi, together with the -pedantic flag).
This is a n00b question and I've seen an answer that does not help me.
I'm running a simple c program (firsty.c) written in textmate:
#include <stdio.h>
int main()
{
printf("hi world.\n");
return 0;
}
I've entered the following into the terminal with the following results:
$ make firsty.c
make: Nothing to be done for `firsty.c'.
$ ./firsty.c
./firsty.c: line 3: syntax error near unexpected token `('
./firsty.c: line 3: `int main()'
probably something simple, but I don't understand what's wrong.
make firsty.c isn't doing anything at all. Try instead make firsty, and then ./firsty.
You are trying to execute the source file. You need to execute the binary file which was hopefully built by make.
I do not know what your makefile is doing, however if it's something like gcc firsty.c the binary output file will be named a.out by default. Use gcc -o executable_name_here to have differently named output file (http://gcc.gnu.org/onlinedocs/gcc/Overall-Options.html#Overall-Options)
Unix (osx at this time) is considering executable file a script, and tries to execute it. On other thing to do would be to remove executable permissions from your source file and then you will not be able to run it.
I think u have not created any Makefile which is used by make command to compile the given source file(s)... so try to write a makefile(http://www.cs.colby.edu/maxwell/courses/tutorials/maketutor/) else try to compile as...
gcc firsty.c -o firstly
then u'll get the executable file in the same directory & u can execute it as
./firstly
take care of the '#'. when you excute a source code file, the OS maybe excute it with the shell. So we get the syntax error.
Try make firsty, it will work and will make a executable with a name firstly.
If this oes not work, try make ./firstly.
Please note that while doing a make as such you need to supply the name of file only and not the extension as .c
The output file is created with the name of file and it will search for corresponding .c file to compile.
In your case
make firsty
This will look for firsty.c to be compiled and create an output file with name firsty.