All Questions
19
questions
148
votes
11
answers
55k
views
What is the difference between $* and $@?
Consider the following code:
foo () {
echo $*
}
bar () {
echo $@
}
foo 1 2 3 4
bar 1 2 3 4
It outputs:
1 2 3 4
1 2 3 4
I am using Ksh88, but I am interested in other common ...
- 20.1k
129
votes
4
answers
52k
views
Why does parameter expansion with spaces without quotes work inside double brackets "[[" but not inside single brackets "["?
I'm confused with using single or double brackets. Look at this code:
dir="/home/mazimi/VirtualBox VMs"
if [[ -d ${dir} ]]; then
echo "yep"
fi
It works perfectly although the string contains a ...
- 3,108
22
votes
2
answers
1k
views
Why escape trivial characters in shell script?
I just opened a legacy shell script (written in old ksh88 on Solaris) and found the following repeated all throughout the code:
[ -f $myfile ] && \rm -f $myfile
The escaping backslash ...
- 20.1k
10
votes
2
answers
24k
views
How do I escape a sub-directory name with an ampersand in it?
Running a kornshell and trying to traverse a directory tree.
Want to cd to a sub-directory named as follows:
-3ab_&_-3dc.img
My question is HOW do I need to escape the ampersand in this name?
I'...
- 101
8
votes
4
answers
49k
views
using awk to split a line on single spaces not multiples
I'm trying to split a line that I have no control over the format of. If parameter 7 and 8 are missing which is possible they will be replaced by a space so I would end up with,
field1 field2 field3 ...
- 161
5
votes
3
answers
3k
views
quotes inside backticks inside quotes in ksh
I'm trying to get the file of the current date with the following command in HP-UX Unix:
$ ls -lrt ABC.LOG* |grep "`date +"%b %d"`"
But, it's giving me the error:
ksh: : cannot execute
grep: can't ...
- 375
3
votes
1
answer
404
views
Why is "${1-"$var"}" (option 6 down below) not mentioned in POSIX?
The only reference I could find in the spec is this:
It would be desirable to include the statement "The characters from an enclosed "${" to the matching '}' shall not be affected by ...
- 2,043
3
votes
2
answers
1k
views
issues with GNU tail -f and combination of commands
$ tail -f /logs/filename.log | awk '!(/list)'
I am able to run this command in GNU Linux flavour
But when I written in a script it is not working.
test.ksh:
variable="/logs/filename.log | awk '!(/...
- 31
2
votes
2
answers
734
views
Meaning of \ before environment variable
In ksh on an old Solaris box I used:
export PS1="$PWD $"
to set the prompt to the current directory. It works great until you cd elsewhere, then you see that it's not evaluating PWD each time. I ...
user13757
2
votes
2
answers
137
views
Awk not rendering any result
My goal is to get the file created in the current month in a directory.
It seems that the command is correct but not rendering any result:
Date=`date '+%b'`
echo $Date
Oct
ls -l | awk -v d="$Date" ...
- 383
1
vote
2
answers
32k
views
How to compare strings in ksh
I want to check the result of a job and execute an action on FAILED.
First: I grep the last word of the line in my application logfile (for the recent processed file ($processedfilename)):
check1=$(...
- 23
1
vote
2
answers
1k
views
Unable to store ascii value in a variable
I am trying to convert hex to decimal to ascii and store it in a variable.
I am using the following code.
HEX=30
DEC=`printf "%d\n" 0x${HEX}`
echo "$DEC"
ASC=`printf \\$(printf '%03o' $DEC)`
echo "$...
- 1,091
1
vote
1
answer
287
views
UNIX KSH - Using double quotes or no quotes when assigning strings with wildcard to a variable?
I am new to UNIX and currently working on a shell script where I will be receiving files with names such as abc_123_date.zip so the file names will be abc_123_12312005. Instead of hardcoding abc_123_*....
- 11
1
vote
3
answers
1k
views
Quoting in command substitution
The command
pdftk FileOne.pdf "File two.pdf" output Combined.pdf
works as expected, merging PDF's One and Two. However, if I put the filenames in a file
FileOne.pdf
"File Two.pdf"
and ...
- 11
1
vote
1
answer
68
views
Why does enclosing a command in double quotes affect aliases?
I have an alias rm='/bin/rm -i' and I know that if I type "rm" filename in the command line, the alias will be ignored somehow and the normal rm command without the -i flag will be called, ...
