Errors occuring on running : I am new to C programming in Linux. I wrote a program, in compiling, no errors are occurred. But on running it is giving too many errors. My program is,
 
     #include <stdio.h>

     typedef struct a{
     char *name;
     int id;
     char *department;
     int num;
     } ab;
    int main()
    {
     ab array[2]={{"Saud",137,"Electronics",500},{"Ebad",111,"Telecom",570}};
     printf("First student data:\n%s\t%d\t%s\t%d",array[0].name,array[0].id,
         array[0].department,array[0].num);

    //ab swap(&array[]);
    }

Errors are,

./newproject: In function `_fini':
(.fini+0x0): multiple definition of `_fini'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crti.o:(.fini+0x0): first defined here
./newproject: In function `data_start':
(.data+0x0): multiple definition of `__data_start'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o:(.data+0x0): first defined here
./newproject: In function `data_start':
(.data+0x8): multiple definition of `__dso_handle'
/usr/lib/gcc/x86_64-linux-gnu/5/crtbegin.o:(.data+0x0): first defined here
./newproject:(.rodata+0x0): multiple definition of `_IO_stdin_used'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o:(.rodata.cst4+0x0): first defined here
./newproject: In function `_start':
(.text+0x0): multiple definition of `_start'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crt1.o:(.text+0x0): first defined here
./newproject: In function `_init':
(.init+0x0): multiple definition of `_init'
/usr/lib/gcc/x86_64-linux-gnu/5/../../../x86_64-linux-gnu/crti.o:(.init+0x0): first defined here
/usr/lib/gcc/x86_64-linux-gnu/5/crtend.o:(.tm_clone_table+0x0): multiple definition of `__TMC_END__'
./newproject:(.data+0x10): first defined here
/usr/bin/ld: error in ./newproject(.eh_frame); no .eh_frame_hdr table will be created.
collect2: error: ld returned 1 exit status
