nm

Common Usage

$ nm
# is equivalent to
$ nm a.out

# output format: <symbol value>, <symbol class>, <symbol name>
$ nm a.o
# sort in a reversed order
$ nm -r a.o
$ nm --reverse-sort a.o

sort by size

# output format: <symbol size>, <symbol class>, <symbol name>
# <symbol size> means the size of the object which the symbol points to
# will not output undefined symbols
$ nm --size-sort a.o
$ nm --size-sort -r a.o
# include <symbol value> in the output
$ nm --size-sort -S a.o

output format (bsd by default)

# SysmtemV
$ nm -f sysv a.o
# POSIX
$ nm -f posix a.o

# [-A | -o | --print-file-name]
# show the source file names of symbols when processing multiple object files
$ nm -A *.o | grep <symbol>
# show the source file names of symbols when processing static linkage library
$ nm -A /usr/lib/libc.a

show dynamic symbols

$ nm -D a.out
$ nm --dynamic a.out

Symbol Class

demangle

$ nm foo.o
00000000 T _Z3fooi
$ nm foo.o | c++filt
00000000 T foo(int)
$ nm --demangle foo.o
00000000 T foo(int)