Expert C Programming

manpage for each, and try running each on a couple of different a.out's—the "hello world" program,
and a big program.

Go through these carefully—investing 15 minutes now in trying each one will save you hours later in
solving a hard bug.

Table 6-1. Tools to Examine Source

Tool Where to

Find It

What It Does

cb Comes with

the compiler

C program beautifier. Run your source through this filter to put it in a

standard layout and indentation. Comes from Berkeley.

indent Does the same things cb does. Comes from AT & T.

cdecl This book Unscrambles C declarations.

cflow Comes with

the compiler

Prints the caller/callee relationships of a program.

cscope Comes with

the compiler

An interactive ASCII-based C program browser. We use it in the OS

group to check the impact of changes to header files. It provides quick

answers to questions like: "How many commands use libthread?" or "Who

are all the kmem readers?"

ctags /usr/bin Creates a tags file for use in vi editor. A tags file speeds up examining

program source by maintaining a table of where most objects are located.

lint Comes with

the compiler

A C program checker.

sccs /usr/ccs/bin A source code version control system.

vgrind /usr/bin A formatter for printing nice C listings.

Doctors can use x-rays, sonograms, arthroscopes, and exploratory operations to look inside their
patients. These tools are the x-rays of the software world.

Table 6-2. Tools to Examine Executables

Tool Where to

Find It

What It Does

dis /usr/ccs/bin Object code disassembler

dump -

Lv

/usr/ccs/bin Prints dynamic linking information

ldd /usr/bin Prints the dynamic libraries this file needs

nm /usr/ccs/bin Prints the symbol table of an object file

strings /usr/bin Looks at the strings embedded in a binary. Useful for looking at the error

messages a binary can generate, built-in file names, and (sometimes)

symbol names or version and copyright information.

sum /usr/bin Prints checksum and block count for a file. An-swers questions like: "Are

two executables the same version?" "Did the transmission go OK?"

Table 6-3. Tools to Help with Debugging