AIX 基础笔记2
*Copying Files
cp source target
cp file1 file2 ... target_dir
# pwd
/tmp/test
# cp /ptc/sp/mvlogs.sh testmv
# ls
test001 test01 test02 test03 test04 testmv
# cp test01 test02 test03 test001
# cd test001
# ls
test01 test02 test03
# cp -i test01 test001
overwrite test001/test01? yes
# cp -R /tmp/test /tmp/test/test001
cp: 0653-441 /tmp/test/test001/test is a descendant of /tmp/test.
Copying results in infinite loop(not copied.)
# cp -R test001 test002
# ls
test001 test002 test01 test02 test03 test04 testmv
# cd test002
# ls
test01 test02 test03 test04 testmv
*Moving and Renaming Files
mv source target
mv file1 file2 ... target_dir
# pwd
/tmp/test
# ls
test001 test01 test02
# mv test02 test001
# ls
test001 test01
# cd test001
# ls
test02
# cd ..
# ls
test001 test01
# mv test01 test03
# ls
test001 test03
# mv test03 test001/test01
# ls
test001
# touch test002
# mv -i test002 test001/test01
overwrite test001/test01? no
# ls
test001 test002
# cd test001
# ls
test01 test02
*Listing File Contents
cat file1 file2 ... //Display all lines
pg filename //Display the files one page at a time
more filename //Display continuous text one screen at a time. With <Enter> pressed, it displays an additional line, and <space bar> , the next screen of text.
wc [-c] [-l] [-w] filename //-c:counts the number of bytes. -l:counts lines. -w:counts words.
# cp /ptc/sp/mvlogs.sh testmv
# ls
test01 test02 testmv
# cat testmv
#!/usr/bin/ksh
echo "delete old logs"
rm -R /pdmdata/logs/apache/*
rm -R /pdmdata/logs/tomcat/*
rm -R /pdmdata/logs/windchill/*
ymd=`date +"%y%m%d"`
echo "make new backup diectory"
mkdir /pdmdata/logs/apache/$ymd
mkdir /pdmdata/logs/tomcat/$ymd
mkdir /pdmdata/logs/windchill/$ymd
if [[ $? != 0 ]]
then
echo "error!Please check first."
exit 1
fi
mv /ptc/Apache/logs/access_log /pdmdata/logs/apache/$ymd
mv /ptc/Apache/logs/error_log /pdmdata/logs/apache/$ymd
mv /ptc/Tomcat/logs/* /pdmdata/logs/tomcat/$ymd
mv /ptc/Windchill/logs/* /pdmdata/logs/windchill/$ymd#
# cat -n testmv //-n flag , with numbers displayed beside each
1 #!/usr/bin/ksh
2 echo "delete old logs"
3 rm -R /pdmdata/logs/apache/*
4 rm -R /pdmdata/logs/tomcat/*
5 rm -R /pdmdata/logs/windchill/*
6 ymd=`date +"%y%m%d"`
7 echo "make new backup diectory"
8 mkdir /pdmdata/logs/apache/$ymd
9 mkdir /pdmdata/logs/tomcat/$ymd
10 mkdir /pdmdata/logs/windchill/$ymd
11 if [[ $? != 0 ]]
12 then
13 echo "error!Please check first."
14 exit 1
15 fi
16 mv /ptc/Apache/logs/access_log /pdmdata/logs/apache/$ymd
17 mv /ptc/Apache/logs/error_log /pdmdata/logs/apache/$ymd
18 mv /ptc/Tomcat/logs/* /pdmdata/logs/tomcat/$ymd
19 mv /ptc/Windchill/logs/* /pdmdata/logs/windchill/$ymd
# wc testmv
18 53 592 testmv
# wc -clw testmv
18 53 592 testmv
*Linking Files
ln source_file target_file
Allows files to have more than one name in the directory structure
Both files reference the same i-node
Cannot be used with directories, cannot span file systems
ln -s source_file target_file
Creates an indirect reference to a file (symbolic link)
Name references the original file's name and path
Can be used with directories and span file systems
# ls -li
total 0
73863 -rw-r--r-- 1 root system 0 Mar 23 16:42 test01
# ln test01 testln01
# ls -li
total 0
73863 -rw-r--r-- 2 root system 0 Mar 23 16:42 test01
73863 -rw-r--r-- 2 root system 0 Mar 23 16:42 testln01
# ln -s test01 testln02
# ls -li
total 0
73863 -rw-r--r-- 2 root system 0 Mar 23 16:42 test01
73863 -rw-r--r-- 2 root system 0 Mar 23 16:42 testln01
73864 lrwxrwxrwx 1 root system 6 Mar 23 16:43 testln02 -> test 01
*Removing Files
rm file1 file2 file3 ...
# touch tet02
# ls
test01 testln01 testln02 tet02
# rm tet02
# ls
test01 testln01 testln02
# touch tet03
# rm -i tet03
rm: Remove tet03? yes
# ls
test01 testln01 testln02
# mkdir test001
# touch test001/testrm
# rm test001
rm: 0653-603 Cannot remove directory test001.
# rm -r test001
# ls
test01 testln01 testln02
*File Protection/Permissions
(1) Every file and directory on the system has file permissions associated with it.
(2) Three permission categories: owner, group, and other
(3) Three bits can be set for each category: read, write, execute (rwx)
*Changing Permissions (Symbolic Notation)
chmod mode filename
u = owner of the file
g = owner's group
o = other users on the system
a = all
+ : add permissions
- : remove permissions
= : clears permissions and sets to mode specified
# touch newfile
# ls -l
total 0
-rw-r--r-- 1 root system 0 Mar 26 16:06 newfile
# chmod go+w newfile
# ls -l newfile
-rw-rw-rw- 1 root system 0 Mar 26 16:06 newfile
# chmod a+x newfile
# ls -l newfile
-rwxrwxrwx 1 root system 0 Mar 26 16:06 newfile
# chmod o-rwx newfile
# ls -l newfile
-rwxrwx--- 1 root system 0 Mar 26 16:06 newfile
*Changing Permissions (Octal Notation)
(1) File and directory permissions can be specified in the symbolic syntax or as an octal number:
User Group Others
Symbolic rwx rw- r--
Binary 111 110 100
4+2+1 4+2+0 4+0+0
Octal 7 6 4
(2) To change permissions so the owner and group have read and write permissions and others read only:
# ls -l newfile
-rwxrwx--- 1 root system 0 Mar 26 16:06 newfile
# chmod 664 newfile
# ls -l
total 0
-rw-rw-r-- 1 root system 0 Mar 26 16:06 newfile
(3) The chart below may help in translating binary to octal for those who are unfamiliar with binary notation:
user |
group |
others |
||||||
r |
w |
x |
r |
w |
x |
r |
w |
x |
| |
| |
| |
| |
| |
| |
| |
| |
| |
400 |
| |
| |
40 |
| |
| |
4 |
| |
| |
200 |
| |
20 |
| |
2 |
| |
|||
100 |
10 |
1 |
*Default File Permissions
(1) The default protections for newly created files and directories are:
File -rw-r--r-- 644
Directory drwxr-xr-x 755
(2) umask
The umask specifies what permission bits will be set on a new file or directory when created. It is an octal number that is used to determine what permission bits a file or directory is created with:
New Directory : 777 - 022 : 755 => rwxr-xr-x
New File: 666 - 022 : 644 => rw-r--r--
The default value of 022 is set in /etc/security/user. It can be changed for all users or for a specific user.