再聊用strace来定位没有core文件的core dump

      我把ulimit -c 给关掉， 如下程序虽然core dump了， 但并不会产生core文件， 看看：

#include <stdio.h>#include <unistd.h>int main(){for(int i = 0; i < 60; i++){printf("aa [%d]\n", i);if(10 == i){int *p = NULL;*p = 0;}sleep(1);}    return 0;}

     结果：

taoge@localhost Desktop> ulimit -c0taoge@localhost Desktop> g++ main.cpp taoge@localhost Desktop> strace -i ./a.out [00374424] execve("./a.out", ["./a.out"], [/* 38 vars */]) = 0[0086e2fd] brk(0)                       = 0x8634000[0086f6d3] mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb78ce000[0086f5d1] access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory)[0086f494] open("/etc/ld.so.cache", O_RDONLY) = 3[0086f45e] fstat64(3, {st_mode=S_IFREG|0644, st_size=49072, ...}) = 0[0086f6d3] mmap2(NULL, 49072, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb78c2000[0086f4cd] close(3)                     = 0[0086f494] open("/usr/lib/libstdc++.so.6", O_RDONLY) = 3[0086f514] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\20F\254\0044\0\0\0"..., 512) = 512[0086f45e] fstat64(3, {st_mode=S_IFREG|0755, st_size=942040, ...}) = 0[0086f6d3] mmap2(0x4a7f000, 969644, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x4a7f000[0086f6d3] mmap2(0x4b60000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0xe0) = 0x4b60000[0086f6d3] mmap2(0x4b66000, 23468, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x4b66000[0086f4cd] close(3)                     = 0[0086f494] open("/lib/libm.so.6", O_RDONLY) = 3[0086f514] read(3, "\177ELF\1\1\1\3\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0p4\243\0004\0\0\0"..., 512) = 512[0086f45e] fstat64(3, {st_mode=S_IFREG|0755, st_size=202040, ...}) = 0[0086f6d3] mmap2(0xa30000, 168064, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xa30000[0086f6d3] mmap2(0xa58000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x27) = 0xa58000[0086f4cd] close(3)                     = 0[0086f494] open("/lib/libgcc_s.so.1", O_RDONLY) = 3[0086f514] read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\240\257\212\0044\0\0\0"..., 512) = 512[0086f45e] fstat64(3, {st_mode=S_IFREG|0755, st_size=122232, ...}) = 0[0086f6d3] mmap2(0x48a9000, 119592, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x48a9000[0086f6d3] mmap2(0x48c6000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1d) = 0x48c6000[0086f4cd] close(3)                     = 0[0086f494] open("/lib/libc.so.6", O_RDONLY) = 3[0086f514] read(3, "\177ELF\1\1\1\3\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0 N\211\0004\0\0\0"..., 512) = 512[0086f45e] fstat64(3, {st_mode=S_IFREG|0755, st_size=1855584, ...}) = 0[0086f6d3] mmap2(0x87e000, 1620360, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x87e000[0086f754] mprotect(0xa03000, 4096, PROT_NONE) = 0[0086f6d3] mmap2(0xa04000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x185) = 0xa04000[0086f6d3] mmap2(0xa07000, 10632, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xa07000[0086f4cd] close(3)                     = 0[0086f6d3] mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb78c1000[0086f6d3] mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb78c0000[0085a552] set_thread_area({entry_number:-1 -> 6, base_addr:0xb78c06d0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0[0086f754] mprotect(0xa04000, 8192, PROT_READ) = 0[0086f754] mprotect(0xa58000, 4096, PROT_READ) = 0[0086f6d3] mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb78bf000[0086f754] mprotect(0x4b60000, 16384, PROT_READ) = 0[0086f754] mprotect(0x876000, 4096, PROT_READ) = 0[0086f711] munmap(0xb78c2000, 49072)    = 0[00d80424] fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0[00d80424] mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb78cd000[00d80424] write(1, "aa [0]\n", 7aa [0])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [1]\n", 7aa [1])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [2]\n", 7aa [2])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [3]\n", 7aa [3])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [4]\n", 7aa [4])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [5]\n", 7aa [5])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [6]\n", 7aa [6])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [7]\n", 7aa [7])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [8]\n", 7aa [8])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [9]\n", 7aa [9])      = 7[00d80424] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0[00d80424] rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0[00d80424] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0[00d80424] nanosleep({1, 0}, 0xbfe789e4) = 0[00d80424] write(1, "aa [10]\n", 8aa [10])     = 8[080484de] --- SIGSEGV (Segmentation fault) @ 0 (0) ---[????????] +++ killed by SIGSEGV (core dumped) +++Segmentation fault (core dumped)taoge@localhost Desktop> ll | grep coretaoge@localhost Desktop> 

      可见， 没有core文件， 也能定位出core,  当然， 我们也可以用strace -p哈。

      夜深人静， 玩玩core, 就这样。