$ ltrace /bin/dd if=/dev/zero of=/dev/null bs=1024 count=10
__libc_start_main(0x804afcc, 5, 0xbfcf3f04, 0x804eeb8, 0x804ef09 <unfinished ...>
setlocale(6, "")                                                     = "C"
bindtextdomain("coreutils", "/usr/share/locale")                     = "/usr/share/locale"
textdomain("coreutils")                                              = "coreutils"
__cxa_atexit(0x804c3ad, 0, 0, 0xbfcf3f04, 0xbfcf3e78)                = 0
getpagesize()                                                        = 4096
getopt_long(5, 0xbfcf3f04, "", NULL, NULL)                           = -1
strchr("if=/dev/zero", '=')                                          = "=/dev/zero"
strchr("of=/dev/null", '=')                                          = "=/dev/null"
strchr("bs=1024", '=')                                               = "=1024"
__ctype_b_loc()                                                      = 0xb7fdd8c4
__errno_location()                                                   = 0xb7fdd8c0
__strtoull_internal(0xbfcf58fa, 0xbfcf3ce4, 10, 0, 0xbfcf3c7c)       = 1024
strchr("count=10", '=')                                              = "=10"
__ctype_b_loc()                                                      = 0xb7fdd8c4
__errno_location()                                                   = 0xb7fdd8c0
__strtoull_internal(0xbfcf5905, 0xbfcf3ce4, 10, 0, 0xbfcf3c7c)       = 10
close(0)                                                             = 0
open64("/dev/zero", 0, 00)                                           = 0
lseek64(0, 0, 0, 1, 0)                                               = 0
__errno_location()                                                   = 0xb7fdd8c0
close(1)                                                             = 0
open64("/dev/null", 577, 0666)                                       = 1
getenv("POSIXLY_CORRECT")                                            = NULL
sigemptyset(0x8051420)                                               = 0
sigaction(10, NULL, 0xbfcf3d78)                                      = 0
sigaddset(0x8051420, 10)                                             = 0
sigaction(2, NULL, 0xbfcf3d78)                                       = 0
sigaddset(0x8051420, 2)                                              = 0
memcpy(0xbfcf3d7c, "\002\002", 128)                                  = 0xbfcf3d7c
sigismember(0x8051420, 10)                                           = 1
sigaction(10, 0xbfcf3d78, NULL)                                      = 0
sigismember(0x8051420, 2)                                            = 1
sigaction(2, 0xbfcf3d78, NULL)                                       = 0
clock_gettime(1, 0xbfcf3ce4, 0, 0, 0)                                = 0
malloc(9219)                                                         = 0x8052038
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
read(0, "", 1024)                                                    = 1024
write(1, "", 1024)                                                   = 1024
free(0x8052038)                                                      = <void>
free(NULL)                                                           = <void>
close(0)                                                             = 0
close(1)                                                             = 0
clock_gettime(1, 0xbfcf39e4, 0xb7ff4518, 0x475034dc, 1)              = 0
dcgettext(0, 0x804ff44, 5, 0, 6)                                     = 0x804ff44
fprintf(0x473cdf80, "%llu+%llu records in\n%llu+%llu "..., ...10+0 records in
10+0 records out
)      = 33
localeconv(0x4d5f434c, 0x41535345, 0x2f534547, 0x65726f63, 0x6c697475) = 0x473ced20
dcngettext(0, 0x80501ec, 0x80501d5, 10240, 5)                        = 0x80501d5
fprintf(0x473cdf80, "%llu bytes (%s) copied", ...10240 bytes (10 kB) copied)                   = 26
localeconv(0x472c0043, 0x472c672c, 0x473b915a, 0x8052028, 9)         = 0x473ced20
sprintf("395.3", "%.1Lf", ...)                                       = 5
sprintf("395", "%.0Lf", ...)                                         = 3
memmove(0xbfcf3ce1, 0xbfcf3a5c, 3, 0xc5ab0acf, 16391)                = 0xbfcf3ce1
dcngettext(0, 0x805021f, 0x805020b, 0, 5)                            = 0x805020b
fprintf(0x473cdf80, ", %g seconds, %s/s\n", ..., 0.025902 seconds, 395 kB/s
)                     = 29
exit(0 <unfinished ...>
__fpending(0x473ce0e0, 0, 0, 0, 0x8052038)                           = 0
fclose(0x473ce0e0)                                                   = -1
__errno_location()                                                   = 0xb7fdd8c0
+++ exited (status 0) +++