Help with getuid Post: 302893905

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Top Forums Programming Help with getuid Post 302893905 by Corona688 on Friday 21st of March 2014 02:35:06 PM

03-21-2014

Registered User

Do you want the program to be run before the C program, or from inside the C program?

From outside:

Code:

cat <<EOF >arg.c
#include <stdio.h>
int main(int argc, char *argv[])
{
        printf("argv[1]=%s\n", argv[1]);
        return(0);
}
EOF

gcc arg.c -o arg

./arg "$(command which prints something)"

From inside:

Code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
       char buf[512];
        FILE *fp=popen("ls", "r");
        while(fgets(buf, 512, fp)) printf("Got line '%s'\n", buf);

        pclose(fp);
}

Last edited by Corona688; 03-21-2014 at 03:43 PM..

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LEARN ABOUT FREEBSD

getuid

GETUID(2)						      BSD System Calls Manual							 GETUID(2)

NAME

     getuid, geteuid -- get user identification

LIBRARY

     Standard C Library (libc, -lc)

SYNOPSIS

     #include <unistd.h>
     #include <sys/types.h>

     uid_t
     getuid(void);

     uid_t
     geteuid(void);

DESCRIPTION

     The getuid() system call returns the real user ID of the calling process.	The geteuid() system call returns the effective user ID of the
     calling process.

     The real user ID is that of the user who has invoked the program.	As the effective user ID gives the process additional permissions during
     execution of ``set-user-ID'' mode processes, getuid() is used to determine the real-user-id of the calling process.

ERRORS

     The getuid() and geteuid() system calls are always successful, and no return value is reserved to indicate an error.

SEE ALSO

     getgid(2), issetugid(2), setgid(2), setreuid(2), setuid(2)

STANDARDS

     The geteuid() and getuid() system calls are expected to conform to ISO/IEC 9945-1:1990 (``POSIX.1'').

HISTORY

     The getuid() and geteuid() functions appeared in Version 7 AT&T UNIX.

BSD
								   June 4, 1993 							       BSD

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getuid