09-29-2012
You need to know that whenever you type in anything on the command line, your shell interprets the command line first and then the corresponding commands are called.
- When your current directory is empty and you issue the command touch test*:
The * character is special to the shell; it's a wildcard which tries to match 0 or more occurrences of any character. So, test* tries to match file-names (in the current directory) starting with test followed by 0 or more occurrences of any character. Since the shell cannot find any such file-names, the pattern is not expanded and the command line remains touch test* and thus, touch creates the file test*.
- rm *
Now, * matches test* and the command line becomes rm test* and the file is removed.
- touch test1* test2*
No file-names match the 2 patterns and the command-line remains as touch test1* test2* and the 2 files are created.
- touch test*
Now, test* matches the 2 files created by 3. So, the command-line becomes touch test1* test2* and the modification and access times of these 2 files are changed by touch.
If you need to create a file name test*, you'll have the escape interpretation of * by the shell by using one of the following ways (or their variations):- touch test\*,or
- touch test'*'
It is dangerous to include
* in file-names.
Last edited by elixir_sinari; 09-29-2012 at 11:19 AM..
This User Gave Thanks to elixir_sinari For This Post:
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Discussion started by: Lokesha
4 Replies
2. Shell Programming and Scripting
Hi,
I've modified the syslogd source to include a thread that will keep track of a timer(or a timer thread). My intention is to check the file size of /var/log/messages in every one minute & if the size is more than 128KB, do a echo " " > /var/log/messages, so that the file size will be set... (7 Replies)
Discussion started by: jockey007
7 Replies
3. AIX
Hello, I'm trying to build a (bff) package from an already installed program (clam antivirus) using mkinstallp. However, mkinstallp fails with "no such file: ./usr/lpp/<package name>/inst_root"
I'm not sure why all files get created ok except for these particular ones. Any help would be... (2 Replies)
Discussion started by: omonte
2 Replies
4. Shell Programming and Scripting
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
Discussion started by: shis100
7 Replies
5. Shell Programming and Scripting
Hi all.
I have a .txt file that I need to sort it
My file is like:
1- 88 chain0 MASTER (FF-TE) FFFF 1962510 /TCK T FD2TQHVTT1 /jtagc/jtag_instreg/updateinstr_reg_1 dff1 (TI,SO)
2- ... (10 Replies)
Discussion started by: Behrouzx77
10 Replies
6. UNIX for Dummies Questions & Answers
Please can you help me understand the significance of providing arguments under sh -s in
> ssh -qtt ${user}@${host} "sh -s "${version}"" < test.sh (4 Replies)
Discussion started by: Sree10
4 Replies
7. Shell Programming and Scripting
I am testing shc to see if it would help with my need.
Im at a point where Im trying to compile and test the "test.ksh" file that comes in the tar ball :
shc-3.8.9> shc -v -r -f test.ksh
shc shll=ksh
shc =-c
shc =exec '%s' "$@"
shc =
shc opts=
shc: cc test.ksh.x.c -o test.ksh.x... (7 Replies)
Discussion started by: popeye
7 Replies
8. UNIX for Dummies Questions & Answers
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies
9. Shell Programming and Scripting
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies