一、問題描述
編寫一個與libpcap有關的程序：test_libpcap.cpp，編譯test_libpcap.o成功。
注：之前已經成功安裝libpcap，libpcap.so.1.5.3的路徑是：/home/test/work/lib；
test_libpcap.cpp的路徑是/home/test/work/test_libpcap。
運行test_libpcap.o出現以下提示：
test_libpcap.o: error while loading shared libraries: libpcap.so.1.5.3: cannot open shared object file: No such file or directory
二、問題解決
注：以下操作均需要root權限
1.定位“libpcap.so.1.5.3”的路徑
# locate libpcap.so.1.5.3 /home/test/work/lib/libpcap.so.1.5.3 /usr/lib/i386-linux-gnu/libpcap.so.1.5.3 /usr/local/lib/libpcap.so.1.5.3
2.將上述路徑中的“/home/test/work/lib/libpcap.so.1.5.3”加入“/etc/ld.so.conf.d”中
# cd /etc/ld.so.conf.d # ls i686-linux-gnu.conf libc.conf # echo "# libpcap default configuration" >> libpcap.conf # echo "/home/test/work/lib/libpcap.so.1.5.3" >> libpcap.conf
3.運行ldconfig命令
# /sbin/ldconfig
4.再次運行test_libpcap.o，成功。
三、參考信息
1.man locate
locate(1) General Commands Manual locate(1) NAME locate - find files by name SYNOPSIS locate [OPTION]... PATTERN... DESCRIPTION locate reads one or more databases prepared by updatedb(8) and writes file names matching at least one of the PATTERNs to standard output, one per line. If --regex is not specified, PATTERNs can contain globbing characters. If any PATTERN contains no globbing characters, locate behaves as if the pattern were *PATTERN*. By default, locate does not check whether files found in database still exist (but it does require all parent directories to exist if the data‐ base was built with --require-visibility no). locate can never report files created after the most recent update of the relevant database. EXIT STATUS locate exits with status 0 if any match was found or if locate was invoked with one of the --limit 0, --help, --statistics or --version options. If no match was found or a fatal error was encountered, locate exits with status 1. Errors encountered while reading a database are not fatal, search con‐ tinues in other specified databases, if any. OPTIONS -A, --all Print only entries that match all PATTERNs instead of requiring only one of them to match. -b, --basename Match only the base name against the specified patterns. This is the opposite of --wholename. -c, --count Instead of writing file names on standard output, write the num‐ ber of matching entries only. -d, --database DBPATH Replace the default database with DBPATH. DBPATH is a :-sepa‐ rated list of database file names. If more than one --database option is specified, the resulting path is a concatenation of the separate paths. An empty database file name is replaced by the default database. A database file name - refers to the standard input. Note that a database can be read from the standard input only once. -e, --existing Print only entries that refer to files existing at the time locate is run. -L, --follow When checking whether files exist (if the --existing option is specified), follow trailing symbolic links. This causes broken symbolic links to be omitted from the output. This is the default behavior. The opposite can be specified using --nofollow. -h, --help Write a summary of the available options to standard output and exit successfully. -i, --ignore-case Ignore case distinctions when matching patterns. -l, --limit, -n LIMIT Exit successfully after finding LIMIT entries. If the --count option is specified, the resulting count is also limited to LIMIT. -m, --mmap Ignored, for compatibility with BSD and GNU locate. -P, --nofollow, -H When checking whether files exist (if the --existing option is specified), do not follow trailing symbolic links. This causes broken symbolic links to be reported like other files. This is the opposite of --follow. -0, --null Separate the entries on output using the ASCII NUL character instead of writing each entry on a separate line. This option is designed for interoperability with the --null option of GNU xargs(1). -S, --statistics Write statistics about each read database to standard output instead of searching for files and exit successfully. -q, --quiet Write no messages about errors encountered while reading and processing databases. -r, --regexp REGEXP Search for a basic regexp REGEXP. No PATTERNs are allowed if this option is used, but this option can be specified multiple times. --regex Interpret all PATTERNs as extended regexps. -s, --stdio Ignored, for compatibility with BSD and GNU locate. -V, --version Write information about the version and license of locate on standard output and exit successfully. -w, --wholename Match only the whole path name against the specified patterns. This is the default behavior. The opposite can be specified using --basename. EXAMPLES To search for a file named exactly NAME (not *NAME*), use locate -b '\NAME' Because \ is a globbing character, this disables the implicit replace‐ ment of NAME by *NAME*. FILES /var/lib/mlocate/mlocate.db The database searched by default. ENVIRONMENT LOCATE_PATH Path to additional databases, added after the default database or the databases specified using the --database option. NOTES The order in which the requested databases are processed is unspeci‐ fied, which allows locate to reorder the database path for security reasons. locate attempts to be compatible to slocate (without the options used for creating databases) and GNU locate, in that order. This is the reason for the impractical default --follow option and for the confus‐ ing set of --regex and --regexp options. The short spelling of the -r option is incompatible to GNU locate, where it corresponds to the --regex option. Use the long option names to avoid confusion. The LOCATE_PATH environment variable replaces the default database in BSD and GNU locate, but it is added to other databases in this imple‐ mentation and slocate. AUTHOR Miloslav Trmac <mitr@redhat.com> SEE ALSO updatedb(8) mlocate Sep 2012 locate(1)
2.man ldconfig
LDCONFIG(8) Linux Programmer's Manual LDCONFIG(8) NAME ldconfig - configure dynamic linker run-time bindings SYNOPSIS /sbin/ldconfig [ -nNvXV ] [ -f conf ] [ -C cache ] [ -r root ] direc‐ tory ... /sbin/ldconfig -l [ -v ] library ... /sbin/ldconfig -p DESCRIPTION ldconfig creates the necessary links and cache to the most recent shared libraries found in the directories specified on the command line, in the file /etc/ld.so.conf, and in the trusted directories (/lib and /usr/lib). The cache is used by the run-time linker, ld.so or ld- linux.so. ldconfig checks the header and filenames of the libraries it encounters when determining which versions should have their links updated. ldconfig will attempt to deduce the type of ELF libs (i.e., libc5 or libc6/glibc) based on what C libs, if any, the library was linked against. Some existing libs do not contain enough information to allow the deduction of their type. Therefore, the /etc/ld.so.conf file format allows the specification of an expected type. This is used only for those ELF libs which we can not work out. The format is "dirname=TYPE", where TYPE can be libc4, libc5, or libc6. (This syntax also works on the command line.) Spaces are not allowed. Also see the -p option. ldconfig should normally be run by the superuser as it may require write permission on some root owned directories and files. OPTIONS -v Verbose mode. Print current version number, the name of each directory as it is scanned, and any links that are created. Overrides quiet mode. -n Only process directories specified on the command line. Don't process the trusted directories (/lib and /usr/lib) nor those specified in /etc/ld.so.conf. Implies -N. -N Don't rebuild the cache. Unless -X is also specified, links are still updated. -X Don't update links. Unless -N is also specified, the cache is still rebuilt. -f conf Use conf instead of /etc/ld.so.conf. -C cache Use cache instead of /etc/ld.so.cache. -r root Change to and use root as the root directory. -l Library mode. Manually link individual libraries. Intended for use by experts only. -p Print the lists of directories and candidate libraries stored in the current cache. FILES /lib/ld.so run-time linker/loader /etc/ld.so.conf File containing a list of colon, space, tab, new‐ line, or comma-separated directories in which to search for libraries. /etc/ld.so.cache File containing an ordered list of libraries found in the directories specified in /etc/ld.so.conf, as well as those found in /lib and /usr/lib. SEE ALSO ldd(1), ld.so(8) COLOPHON This page is part of release 3.54 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/. GNU 2012-05-10 LDCONFIG(8)
四、原文網址[原文發布於2014-09-20 09:56]
http://www.cnblogs.com/tom-and-jerry/p/3978092.html
【完結】