| 词条 | Find (Unix) |
| 释义 |
| name = find | logo = | screenshot = | screenshot size = | caption = | author = Dick Haight | developer = AT&T Bell Laboratories | released = | latest release version = | latest release date = | operating system = Unix and Unix-like | genre = Command | license = | website = }} In Unix-like and some other operating systems, The related Historyfind appeared in Version 5 Unix as part of the Programmer's Workbench project, and was written by Dick Haight alongside cpio,[1] which were designed to be used together.[2]Find syntax{{expand section|date=August 2008}}$ find [-H] [-L] [-P] path... [expression] The three options control how the At least one path must precede the expression. Expression elements are whitespace-separated and evaluated from left to right. They can contain logical elements such as AND (‑and or ‑a) and OR (‑or ‑o) as well as more complex predicates. The GNU POSIX protection from infinite outputReal-world file systems often contain looped structures created through the use of hard or soft links. The POSIX standard requires that {{Quotation|The directory that is an ancestor of the last file encountered. When it detects an infinite loop, its position in the hierarchy or terminate. }} OperatorsOperators can be used to enhance the expressions of the find command. Operators are listed in order of decreasing precedence:
$ find . -name 'fileA_*' -o -name 'fileB_*' This command searches the current working directory tree for files whose names start with "fileA_" or "fileB_". $ find . -name 'foo.cpp' '!' -path '.svn' This command searches the current working directory tree except the subdirectory tree ".svn" for files whose name is "foo.cpp". We quote the Type filter explanationVarious type filters are supported by $ find -type x where x may be any of:
The configuration switches listed in bold are most commonly used. Examples{{howto|section|date=September 2016}}From the current working directory$ find . -name 'my*' This searches the current working directory tree for files whose names start with my. The single quotes avoid the shell expansion—without them the shell would replace my* with the list of files whose names begin with my in the current working directory. In newer versions of the program, the directory may be omitted, and it will imply the current working directory. Regular files only$ find . -name 'my*' -type f This limits the results of the above search to only regular files, therefore excluding directories, special files, symbolic links, etc. my* is enclosed in single quotes (apostrophes) as otherwise the shell would replace it with the list of files in the current working directory starting with my… CommandsThe previous examples created listings of results because, by default, $ find . -name 'my*' -type f -ls This prints extended file information. Search all directories$ find / -name myfile -type f -print This searches every directory for a regular file whose name is myfile and prints it to the screen. It is generally not a good idea to look for files this way. This can take a considerable amount of time, so it is best to specify the directory more precisely. Some operating systems may mount dynamic file systems that are not congenial to Search all but one subdirectory tree$ find / -path excluded_path -prune -o -type f -name myfile -print This searches every directory except the subdirectory tree excluded_path (full path including the leading /) that is pruned by the Specify a directory$ find /home/weedly -name myfile -type f -print This searches the /home/weedly directory tree for regular files named myfile. You should always specify the directory to the deepest level you can remember. Search several directories$ find local /tmp -name mydir -type d -print This searches the local subdirectory tree of the current working directory and the /tmp directory tree for directories named mydir. Ignore errorsIf you're doing this as a user other than root, you might want to ignore permission denied (and any other) errors. Since errors are printed to stderr, they can be suppressed by redirecting the output to /dev/null. The following example shows how to do this in the bash shell: $ find / -name myfile -type f -print 2> /dev/null If you are a csh or tcsh user, you cannot redirect stderr without redirecting stdout as well. You can use sh to run the $ sh -c "find / -name myfile -type f -print 2> /dev/null" An alternate method when using csh or tcsh is to pipe the output from stdout and stderr into a grep command. This example shows how to suppress lines that contain permission denied errors. $ find . -name myfile |& grep -v 'Permission denied' Find any one of differently named files$ find . \\( -name '*jsp' -o -name '*java' \\) -type f -ls The Execute an action$ find /var/ftp/mp3 -name '*.mp3' -type f -exec chmod 644 {} \\; This command changes the permissions of all regular files whose names end with .mp3 in the directory tree /var/ftp/mp3. The action is carried out by specifying the statement Note that the command itself should not be quoted; otherwise you get error messages like find: echo "mv ./3bfn rel071204": No such file or directory which means that If you will be executing over many results, it is more efficient to use a variant of the exec primary that collects filenames up to {{mono|ARG_MAX}} and then executes COMMAND with a list of filenames. $ find . -exec COMMAND {} + This will ensure that filenames with whitespaces are passed to the executed {{code|COMMAND}} without being split up by the shell. Delete files and directoriesThe Delete empty files and print the names (note that $ find . -empty -delete -print Delete empty regular files: $ find . -type f -empty -delete Delete empty directories: $ find . -type d -empty -delete Delete empty files named 'bad': $ find . -name bad -empty -delete Warning. — The $ find . -delete # this deletes all in . Search for a stringThis command will search all files from the /tmp directory tree for a string: $ find /tmp -type f -exec grep 'search string' /dev/null '{}' \\+ The /dev/null argument is used to show the name of the file before the text that is found. Without it, only the text found is printed. GNU $ grep -r 'search string' /tmp Example of search for "LOG" in jsmith's home directory tree: $ find ~jsmith -exec grep LOG '{}' /dev/null \\; -print /home/jsmith/scripts/errpt.sh:cp $LOG $FIXEDLOGNAME /home/jsmith/scripts/errpt.sh:cat $LOG /home/jsmith/scripts/title:USER=$LOGNAME Example of search for the string "ERROR" in all XML files in the current working directory tree: $ find . -name "*.xml" -exec grep "ERROR" /dev/null '{}' \\+ The double quotes (" ") surrounding the search string and single quotes (' ') surrounding the braces are optional in this example, but needed to allow spaces and some other special characters in the string. Note with more complex text (notably in most popular shells descended from `sh` and `csh`) single quotes are often the easier choice, since double quotes do not prevent all special interpretation. Quoting filenames which have English contractions demonstrates how this can get rather complicated, since a string with an apostrophe in it is easier to protect with double quotes: $ find . -name "file-containing-can't" -exec grep "can't" '{}' \\; -print Search for all files owned by a user$ find . -user Search in case insensitive modeNote that $ find . -iname 'MyFile*' If the $ find . -name '[mM][yY][fF][iI][lL][eE]*' This uses Perl to build the above command for you (though in general this kind of usage is dangerous, since special characters are not properly quoted before being fed into the standard input of `sh`): $ echo 'MyFile*' | perl -pe 's/([a-zA-Z])/[\\L\\1\\U\\1]/g;s/(.*)/find . -name \\1/' | sh Search files by sizeSearching files whose size is between 100 kilobytes and 500 kilobytes: $ find . -size +100k -a -size -500k Searching empty files: $ find . -size 0k Searching non-empty files: $ find . ! -size 0k Search files by name and size$ find /usr/src ! \\( -name '*,v' -o -name '.*,v' \\) '{}' \\; -print This command will search the /usr/src directory tree. All files that are of the form '*,v' and '.*,v' are excluded. Important arguments to note are in the tooltip that is displayed on mouse-over. for file in `find /opt \\( -name error_log -o -name 'access_log' -o -name 'ssl_engine_log' -o -name 'rewrite_log' -o -name 'catalina.out' \\) -size +300000k -a -size -5000000k`; do cat /dev/null > $file done The units should be one of [bckw], 'b' means 512-byte blocks, 'c' means byte, 'k' means kilobytes and 'w' means 2-byte words. The size does not count indirect blocks, but it does count blocks in sparse files that are not actually allocated. Related utilities
See also
References1. ^{{cite techreport |first1=M. D. |last1=McIlroy |authorlink1=Doug McIlroy |year=1987 |url=http://www.cs.dartmouth.edu/~doug/reader.pdf |title=A Research Unix reader: annotated excerpts from the Programmer's Manual, 1971–1986 |series=CSTR |number=139 |institution=Bell Labs}} 2. ^{{Cite web|title = libarchive/libarchive|url = https://github.com/libarchive/libarchive/wiki/FormatCpio|website = GitHub|accessdate = 2015-10-04}} External links
3 : Information retrieval systems|Standard Unix programs|Unix SUS2008 utilities |
| 随便看 |
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。