@sagaxu
Loaded plugins: auto-update-debuginfo, fastestmirror
enabling epel-debuginfo
enabling remi-safe-debuginfo
enabling base-debuginfo
enabling webtatic-debuginfo
Loading mirror speeds from cached hostfile
* base: mirrors.linode.com
* epel: linux.mirrors.es.net
* epel-debuginfo: linux.mirrors.es.net
* extras: mirrors.linode.com
* remi-safe: repo1.sea.innoscale.net
* updates: mirrors.linode.com
* webtatic: us-east.repo.webtatic.com
* webtatic-debuginfo: us-east.repo.webtatic.com
Could not find debuginfo for main pkg: httpd-2.4.6-67.el7.centos.5.x86_64
Package apr-debuginfo-1.4.8-3.el7.x86_64 already installed and latest version
Package apr-util-debuginfo-1.5.2-6.el7.x86_64 already installed and latest version
Package glibc-debuginfo-2.17-196.el7.x86_64 already installed and latest version
Package libdb-debuginfo-5.3.21-20.el7.x86_64 already installed and latest version
Package expat-debuginfo-2.1.0-10.el7_3.x86_64 already installed and latest version
Package lua-debuginfo-5.1.4-15.el7.x86_64 already installed and latest version
Package pcre-debuginfo-8.32-17.el7.x86_64 already installed and latest version
Package libselinux-debuginfo-2.5-11.el7.x86_64 already installed and latest version
Package systemd-debuginfo-219-42.el7_4.1.x86_64 already installed and latest version
Package zlib-debuginfo-1.2.7-17.el7.x86_64 already installed and latest version
No debuginfo packages available to install

已经装好了，现在需要如何查看呢？

@sagaxu 你的意思是重装 httpd 和 php ？我是直接用 yum install 安装的，手动编译的话，不熟悉，能否给一个完整的编译教程呢？谢谢。。

[Wed Oct 18 01:39:45.016354 2017] [core:notice] [pid 16586] AH00051: child pid 16587 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:46.020711 2017] [core:notice] [pid 16586] AH00051: child pid 16589 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:48.024828 2017] [core:notice] [pid 16586] AH00051: child pid 16590 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:49.028980 2017] [core:notice] [pid 16586] AH00051: child pid 16588 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:49.029066 2017] [core:notice] [pid 16586] AH00051: child pid 16591 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:50.030227 2017] [core:notice] [pid 16586] AH00051: child pid 16592 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:51.033353 2017] [core:notice] [pid 16586] AH00051: child pid 16594 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:52.040236 2017] [core:notice] [pid 16586] AH00051: child pid 16595 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:53.041442 2017] [core:notice] [pid 16586] AH00051: child pid 16596 exit signal Segmentation fault (11), possible coredump in /tmp
[Wed Oct 18 01:39:55.046361 2017] [core:notice] [pid 16586] AH00051: child pid 16598 exit signal Segmentation fault (11), possible coredump in /tmp

@sagaxu
我是参考这个页面生成的 coredump 文件：
http://mattharris.org/2016/02/09/http-2-4-ah00051-child-pid-22471-exit-signal-segmentation-fault-11/

@sagaxu

[root@li1007-178 tmp]# gdb /usr/sbin/httpd core.16598
GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-100.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <******>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<*****>...
Reading symbols from /usr/sbin/httpd...Reading symbols from /usr/sbin/httpd...(no debugging symbols found)...done.
(no debugging symbols found)...done.
[New LWP 16598]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib64/libthread_db.so.1".
Core was generated by `/usr/sbin/httpd -DFOREGROUND'.
Program terminated with signal 11, Segmentation fault.
#0 0x00007f96255fd721 in zend_std_write_property () from /etc/httpd/modules/libphp5.so
Missing separate debuginfos, use: debuginfo-install httpd-2.4.6-67.el7.centos.5.x86_64

出来是这样的，libphp5.so 这个文件是有的。我也单独在 httpd.conf 里加载了
LoadModule php5_module /etc/httpd/modules/libphp5.so
<FilesMatch \.php$>
SetHandler application/x-httpd-php
</FilesMatch>

但是还是同样的错误。

@sagaxu

GNU gdb (GDB) Red Hat Enterprise Linux 7.6.1-100.el7
Copyright (C) 2013 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
(gdb) backtrace
No stack.
(gdb)

是不是这样的呢，没有什么内容呢

还是文件夹权限问题。问题解决，结贴。

谢谢各位的回复。不能使用浏览器或其他客户端进行打印。
@bertonzh 没有看到可以在线测试的，我再看看。谢谢。

搞定，结贴，不回复。谢谢。

@snnn 并不是我改过某个值，我安装好后，就报错了。后来修改的内容，也都是通过网络查询的，只是没有解决到问题。谢谢你的回复。

@ToughGuy
@gstqc
@snnn 谢了，我还原了默认的版本 my.cnf 。然后设置了 swap，就可以了。

@uuair 考虑过学 python。

@SuperMild
@zke1e
谢了哈。

@WTT 收录的速度还不清楚，权重的话，如何查询呢？用站长网查询的，是 1，权重不高。

@CheungKe 中文的问题，可以解决，装上中文的语言包，就解决了，至少我目前还没遇到过乱码的问题。

@SolidZORO
@xu1ming dpi 用的是默认的 96，没有单独配置。我用 px 换算成 mm，按照 mm = (px * 25.4) / dpi （网上的公式），这样出来的结果还需要再除以 3.8，在生成的 pdf 时，高度才算合理，但是这样的话，不晓得整体的页面高度了，页面也是用的默认设置 A4，按照 A4 的高度计算，生成的 PDF 文件就不对了，中间的内容高度为负数了。。

我用的 firefox 版本是 54.0.1 (64-bit) mac，希望此贴对以后遇到类似问题的朋友有所帮助。