Changing password using execv

Hi...
I need to change the user's passwd from inside a C program.The execv function seems to be the only way to execute linux commands from inside the program.however running passwd (using execv) is not working.I suppose this is because we cannot specify the arguments on the command line for the password command.Other commands work fine.
Any way out?
Thanks for all help in advance.

If you want to issue the passwd command from within C program, look at system(3). Elsewise, look at getpass(3) for user input and the functions getpwent(3), getpwnam(3) and putpwent(3) for manipulating the /etc/passwd file directly. Hope this helps. -mk

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If it ain't broke, fix it till it is.

Hi,
the 'system' call works.Thank you.