Regarding cuserid() function in 'C'

Hi,

I am doing a (Make gapw), where I have the following line of code at Line No.96 :-

96 DISCARD strcpy(user , (char*) cuserid((char*)0));

But I am not able to compile due to the only 1 following error :-

gapw.c: In function `main':
gapw.c:96: warning: cast to pointer from integer of different size

I included #include <stdlib.h> and #include <libgen.h>, in the file, but still I am not able to compile.

I think, there is a problem with the usage of cuserid() function.

Request you to please help me to debug the error.

Thanks in advance.

Best Regards,
Marconi

What platform are you on?
cuserid() will be removed some time in the future so it is recommended to use its replacements like getpwuid() or getlogin().

Hi,

I am currently on OS :- Red Hat Linux Version 3.0. The script I am running is a HP Tru64 Unix compatible script
which I am trying to run on the Linux Version 3.0.

Instead of :- DISCARD strcpy(user , (char*) cuserid((char*)0));

I used each of the following as per your suggestion :-

 DISCARD strcpy\(user, \(char*\) getlogin\(\(char*\)0\)\);
                             
                             or                               

 DISCARD strcpy\(user , \(char*\) getpwuid\(getuid\(\(char*\)0\)\)\); 

but still its showing me the following errors :-

$ make gapw
cc -c -o gapw.o gapw.c
gapw.c: In function `main':
gapw.c:101: error: too many arguments to function `getlogin'
make: *** [gapw.o] Error 1

                                or

$ make gapw
cc -c -o gapw.o gapw.c
gapw.c: In function `main':
gapw.c:102: error: too many arguments to function `getuid'
gapw.c:102: warning: cast to pointer from integer of different size
make: *** [gapw.o] Error 1

Request you to pls give ur inputs.

Regards,
Marconi.

Are you including the required headers for getlogin() and/or getpwuid()?

getlogin() requires <unistd.h>
getpwuid() requires <sys/types.h> and <pwd.h>

corrected syntax for getlogin

/* top of file */
#include <unistd.h>
/* ..... some of your code here down to line 101 */
strcpy(user , getlogin() ); 

Hi,

I had already added the 3 header files as suggested by murphy as follows :-

#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <limits.h>
#include "ifile.h"
#include <libgen.h>
#include <stdlib.h>
#include <pwd.h>

The earlier code had cuserid() as follows :-

1) DISCARD strcpy(user , (char*) cuserid((char*)0));

As cuserid() is not a valid function in linux, I can use either getlogin() or getpwuid()

As per Jim's suggestion, if I put the code like this :-

2) DISCARD strcpy(user, getlogin());

I don't have any errors, as follows :-

$ gcc gapw.c
/tmp/cc6K9ODh.o(.text+0x21d): In function `main':
: undefined reference to `getprofilestring'
/tmp/cc6K9ODh.o(.text+0x2ec): In function `main':
: undefined reference to `getprofilestring'
collect2: ld returned 1 exit status

$ make clean
rm -f getkey.o ifile.o bitt.o getkey getapp \
putkey getall getappkeys gapw filetime filetime.o gapw.o bitt \
libExtRelan.so envi envi.o

$ make gapw
cc -c -o gapw.o gapw.c
cc -c -o ifile.o ifile.c
cc -o gapw gapw.o ifile.o -lc_r
/usr/bin/ld: cannot find -lc_r
collect2: ld returned 1 exit status
make: *** [gapw] Error 1

$

But, I think the logic will be changed when we compare the code at 1) and 2), above.

Also, when I do a gcc gapw.c, I still get the above errors, though there are no errors
when I do a make gapw.

Request you to please give your inputs.

Thanks a lot in advance.

Best Regards,
Marconi.