Problems using the dbm database in C

[theDentist]

I am trying to use the dbm database (gdbm and ndbm)and wrote a simple program to see if I was successful in defining the data types and functions with the correct headers and libraries. I successfully defined the DBM and datum types using the gdbm-ndbm.h header ( I am using Ubuntu )but get an undefined error when I code the functions, like for example, dbm_open(). I would have thought the functions would have their prototypes in the same header? Can anyone give me advice concerning headers that I need, or any libraries when I run the compiler. :(

Peter

[Woei]

I am trying to use the dbm database (gdbm and ndbm)and wrote a simple program to see if I was successful in defining the data types and functions with the correct headers and libraries. I successfully defined the DBM and datum types using the gdbm-ndbm.h header ( I am using Ubuntu )but get an undefined error when I code the functions, like for example, dbm_open(). I would have thought the functions would have their prototypes in the same header? Can anyone give me advice concerning headers that I need, or any libraries when I run the compiler. :(


Well, you're not giving us much to go on apart from an 'undefined' error. You really should've included gcc's error output. libgdbm is quite a small library, and it comes with a pretty good tutorial:

apt-get install libgdbm-dev pinfo
pinfo gdbm


What you're probably missing is -l gdbm as a switch to your gcc invocation. Something like gcc foo.c -o bar -Wall -pedantic -lgdbm should do. Basically, you have to tell gcc (or rather, the linker invoked by gcc) explicitly to link the gdbm library with the object code from your program. See man ld for a discussion.