[chhaba]

Hi all,

I have created a library file suppose lib.o
I want to create a function in this library, so that any program compiled with this library will print the name of the executable.

e.g.
myprog.c

int main(){

function_from_liberary();
}

and liberary file
lib.c contains

void function_from_liberary() {

printf ("\nExecutable name is %s",what_to_write_here);
}


i compile using

gcc -c lib.c

gcc -g -o myprog myprog.c lib.o

Please help

Thanx and regards

[rajeshk]

void function_from_liberary() {

printf ("\nExecutable name is %s",argv[0]);
}

[the_unforgiven]

Originally Posted by rajeshk

void function_from_liberary() {

printf ("\nExecutable name is %s",argv[0]);
}

No, this is not possible - argv is local to main() only - if main() is declared as

int main(int argc, char** argv)

- which is the de-facto standard.

However, you can make function_from_library() take a const char* - which would be passed from main() as argv[0].

[the_unforgiven]

Originally Posted by the_unforgiven

No, this is not possible - argv is local to main() only - if main() is declared as

int main(int argc, char** argv)

- which is the de-facto standard.

However, you can make function_from_library() take a const char* - which would be passed from main() as argv[0].

Or, better still, you could use the file /proc/<PID>/cmdline - pid can be got with getpid().

[chhaba]

Hi all,
I have changed my program as follows. but it gives error:
line 7: error: dereferencing pointer to incomplete type

1. #include<stdio.h>
2. #include<sys/stat.h>
3. #include<stdlib.h>
4. void execname() {
5. struct task_struct *my;
6. my = find_task_by_id(getpid());
7. printf("%s",my->comm); error: dereferencing pointer to incomplete type
8.
9. }
10. int main()
11. {
12. execname();
13. }


what's wrong with it

[suppressingfire]

__progname (and __progname_full) are possible ways to access the executable's name at runtime without having to store off values from argv**. I don't believe it's entirely standard, but it's available and is what glibc's assert uses.

extern const char *__progname;

void print_progname() {
printf("Name: %s\n", __progname);
}