How to find something
Most time, we need to find something in the computer, or in file content, no matter what, it was a really important skill for you.
Regex
Very Important , just go to this site https://www.hackerrank.com/domains/regex, and do it completely. and wildcard just similar like it, but absolutely not the same one.
- find
find [path] [options] [tests] [actions]
$find / -type f -exec grep -H 'text-to-find-here' {} \;
# blow code was copyed from http://alvinalexander.com/unix/edu/examples/
basic 'find file' commands
--------------------------
find / -name foo.txt -type f -print # full command
find / -name foo.txt -type f # -print isn't necessary
find / -name foo.txt # don't have to specify "type==file"
find . -name foo.txt # search under the current dir
find . -name "foo.*" # wildcard
find . -name "*.txt" # wildcard
find /users/al -name Cookbook -type d # search '/users/al'
search multiple dirs
--------------------
find /opt /usr /var -name foo.scala -type f # search multiple dirs
case-insensitive searching
--------------------------
find . -iname foo # find foo, Foo, FOo, FOO, etc.
find . -iname foo -type d # same thing, but only dirs
find . -iname foo -type f # same thing, but only files
find files with different extensions
------------------------------------
find . -type f \( -name "*.c" -o -name "*.sh" \) # *.c and *.sh files
find . -type f \( -name "*cache" -o -name "*xml" -o -name "*html" \) # three patterns
find files that don't match a pattern (-not)
--------------------------------------------
find . -type f -not -name "*.html" # find all files not ending in ".html"
find files by text in the file (find + grep)
--------------------------------------------
find . -type f -name "*.java" -exec grep -l StringBuffer {} \; # find StringBuffer in all *.java files
find . -type f -name "*.java" -exec grep -il string {} \; # ignore case with -i option
find . -type f -name "*.gz" -exec zgrep 'GET /foo' {} \; # search for a string in gzip'd files
5 lines before, 10 lines after grep matches
-------------------------------------------
find . -type f -name "*.scala" -exec grep -B5 -A10 'null' {} \;
(see http://alvinalexander.com/linux-unix/find-grep-print-lines-before-after-search-term)
find files and act on them (find + exec)
----------------------------------------
find /usr/local -name "*.html" -type f -exec chmod 644 {} \; # change html files to mode 644
find htdocs cgi-bin -name "*.cgi" -type f -exec chmod 755 {} \; # change cgi files to mode 755
find . -name "*.pl" -exec ls -ld {} \; # run ls command on files found
find and copy
-------------
find . -type f -name "*.mp3" -exec cp {} /tmp/MusicFiles \; # cp *.mp3 files to /tmp/MusicFiles
copy one file to many dirs
--------------------------
find dir1 dir2 dir3 dir4 -type d -exec cp header.shtml {} \; # copy the file header.shtml to those dirs
find and delete
---------------
find . -type f -name "Foo*" -exec rm {} \; # remove all "Foo*" files under current dir
find . -type d -name CVS -exec rm -r {} \; # remove all subdirectories named "CVS" under current dir
find files by modification time
-------------------------------
find . -mtime 1 # 24 hours
find . -mtime -7 # last 7 days
find . -mtime -7 -type f # just files
find . -mtime -7 -type d # just dirs
find files by modification time using a temp file
-------------------------------------------------
touch 09301330 poop # 1) create a temp file with a specific timestamp
find . -mnewer poop # 2) returns a list of new files
rm poop # 3) rm the temp file
find with time: this works on mac os x
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find / -newerct '1 minute ago' -print
find and tar
------------
find . -type f -name "*.java" | xargs tar cvf myfile.tar
find . -type f -name "*.java" | xargs tar rvf myfile.tar
(see http://alvinalexander.com/blog/post/linux-unix/using-find-xargs-tar-create-huge-archive-cygwin-linux-unix
for more information)
find, tar, and xargs
--------------------
find . -name -type f '*.mp3' -mtime -180 -print0 | xargs -0 tar rvf music.tar
(-print0 helps handle spaces in filenames)
(see http://alvinalexander.com/mac-os-x/mac-backup-filename-directories-spaces-find-tar-xargs)
find and pax (instead of xargs and tar)
---------------------------------------
find . -type f -name "*html" | xargs tar cvf jw-htmlfiles.tar -
find . -type f -name "*html" | pax -w -f jw-htmlfiles.tar
(see http://alvinalexander.com/blog/post/linux-unix/using-pax-instead-of-tar)
- grep/egrep
code from reference 3, and my suggestion is egrep....
search for a string in one or more files
----------------------------------------
grep 'fred' /etc/passwd # search for lines containing 'fred' in /etc/passwd
grep fred /etc/passwd # quotes usually not when you don't use regex patterns
grep null *.scala # search multiple files
case-insensitive
----------------
grep -i joe users.txt # find joe, Joe, JOe, JOE, etc.
regular expressions
-------------------
grep '^fred' /etc/passwd # find 'fred', but only at the start of a line
grep '[FG]oo' * # find Foo or Goo in all files in the current dir
grep '[0-9][0-9][0-9]' * # find all lines in all files in the current dir with three numbers in a row
display matching filenames, not lines
-------------------------------------
grep -l StartInterval *.plist # show all filenames containing the string 'StartInterval'
grep -il StartInterval *.plist # same thing, case-insensitive
show matching line numbers
--------------------------
grep -n we gettysburg-address.txt # show line numbers as well as the matching lines
lines before and after grep match
---------------------------------
grep -B5 "the living" gettysburg-address.txt # show all matches, and five lines before each match
grep -A10 "the living" gettysburg-address.txt # show all matches, and ten lines after each match
grep -B5 -A5 "the living" gettysburg-address.txt # five lines before and ten lines after
reverse the meaning
-------------------
grep -v fred /etc/passwd # find any line *not* containing 'fred'
grep -vi fred /etc/passwd # same thing, case-insensitive
grep in a pipeline
------------------
ps auxwww | grep httpd # all processes containing 'httpd'
ps auxwww | grep -i java # all processes containing 'java', ignoring case
ls -al | grep '^d' # list all dirs in the current dir
search for multiple patterns
----------------------------
egrep 'apple|banana|orange' * # search for multiple patterns, all files in current dir
egrep -i 'apple|banana|orange' * # same thing, case-insensitive
egrep 'score|nation|liberty|equal' gettysburg-address.txt # all lines matching multiple patterns
locate -i calendar | grep Users | egrep -vi 'twiki|gif|shtml|drupal-7|java|PNG' # oh yeah
(see http://alvinalexander.com/linux-unix/linux-egrep-multiple-regular-expressions-regex)
multiple search strings, multiple filename patterns
---------------------------------------------------
grep -li "jtable" $(find . -name "*.java,v" -exec grep -li "prevayl" {} \;) # find all files named "*.java,v" containing both
# 'prevayl' and 'jtable'
grep + find
-----------
find . -type f -exec grep -il 'foo' {} \; # print all filenames of files under current dir containing 'foo', case-insensitive
recursive grep search
---------------------
grep -rl 'null' . # very similar to the previous find command; does a recursive search
grep -ril 'null' /home/al/sarah /var/www # search multiple dirs
egrep -ril 'aja|alvin' . # multiple patterns, recursive
(see http://alvinalexander.com/linux-unix/recursive-grep-r-searching-egrep-find)
grep gzip files
---------------
zgrep foo myfile.gz # all lines containing the pattern 'foo'
zgrep 'GET /blog' access_log.gz # all lines containing 'GET /blog'
zgrep 'GET /blog' access_log.gz | more # same thing, case-insensitive
Reference:
- find and grep : http://iami.xyz/find-Useage/
- find useage collections : http://alvinalexander.com/unix/edu/examples/find.shtml
- grep useage collections: http://alvinalexander.com/unix/edu/examples/grep.shtml