https://blogs.oracle.com/solairo/entry/ksplice_strace
Strace -- システム管理者の顕微鏡
ex.netstat -a コマンドを実行するときに読み込まれるファイルとか見てみる。/etc/servicesが読み込まれていた
strace -e open netstat -a
open("/etc/ld.so.cache", O_RDONLY) = 3
open("/lib/libselinux.so.1", O_RDONLY) = 3
open("/lib/libc.so.6", O_RDONLY) = 3
open("/lib/libdl.so.2", O_RDONLY) = 3
open("/lib/libsepol.so.1", O_RDONLY) = 3
open("/etc/selinux/config", O_RDONLY|O_LARGEFILE) = 3
open("/proc/mounts", O_RDONLY|O_LARGEFILE) = 3
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
open("/proc/net/tcp", O_RDONLY) = 3
open("/etc/nsswitch.conf", O_RDONLY) = 4
open("/etc/ld.so.cache", O_RDONLY) = 4
open("/lib/libnss_files.so.2", O_RDONLY) = 4
open("/etc/services", O_RDONLY) = 4
open("/etc/protocols", O_RDONLY) = 4
tcp 0 0 *:mysql *:* LISTEN
tcp 0 0 *:pop3 *:* LISTEN
tcp 0 0 *:http *:* LISTEN
tcp 0 0 *:ssh *:* LISTEN
tcp 0 0 *:smtp *:* LISTEN
open("/etc/resolv.conf", O_RDONLY) = 4
open("/etc/host.conf", O_RDONLY) = 4
open("/etc/hosts", O_RDONLY) = 4
open("/etc/hosts", O_RDONLY) = 4
open("/etc/ld.so.cache", O_RDONLY) = 4
open("/lib/libnss_dns.so.2", O_RDONLY) = 4
open("/lib/libresolv.so.2", O_RDONLY) = 4
tcp 0 1388 www34237u.sakura.ne.jp:ssh 219.117.253.234.stati:60168 ESTABLISHED
open("/proc/net/tcp6", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/udp", O_RDONLY) = 3
udp 0 0 www34237u.sakura.ne.jp:ntp *:*
open("/etc/hosts", O_RDONLY) = 4
udp 0 0 localhost.localdomain:ntp *:*
udp 0 0 *:ntp *:*
open("/proc/net/udp6", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/sctp/eps", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/sctp/assocs", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/raw", O_RDONLY) = 3
open("/proc/net/raw6", O_RDONLY) = -1 ENOENT (No such file or directory)
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
open("/proc/net/unix", O_RDONLY) = 3
unix 2 [ ACC ] STREAM LISTENING 3484 @ISCSIADM_ABSTRACT_NAMESPACE
unix 2 [ ACC ] STREAM LISTENING 3470 @ISCSID_UIP_ABSTRACT_NAMESPACE
unix 7 [ ] DGRAM 3688 /dev/log
unix 2 [ ] DGRAM 1190 @/org/kernel/udev/udevd
unix 2 [ ACC ] STREAM LISTENING 3768 /var/run/acpid.socket
unix 2 [ ACC ] STREAM LISTENING 3878 /var/lib/mysql/mysql.sock
unix 2 [ ] DGRAM 28790175
unix 3 [ ] STREAM CONNECTED 28790119
unix 3 [ ] STREAM CONNECTED 28790118
unix 2 [ ] DGRAM 28790113
unix 2 [ ] DGRAM 3990
unix 2 [ ] DGRAM 3909
unix 2 [ ] DGRAM 3696
open("/proc/net/ipx", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/ax25", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/x25", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/x25", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/proc/net/nr", O_RDONLY) = -1 ENOENT (No such file or directory)
