No, it is not. A "variable" is something like "$name" or "${name}", where "name" is a name you choose. "$xyz" might be a variable, but "v$xyz" is a literal "v" followed by the content of a variable with the name "xyz".
Quote:
Originally Posted by green_k
the file name like v$xyz_xxxx_xxxx.txt.
OK, but is the "$xyz" in this filename now meant literally or should that signify the variable portion of the filename which you want to transport via the variable? If the first is the case a simple quotation will suffice, because this is what it is for - inside of (single) quotes the "$" loses its special meaning to the shell and reverts back to a normal character:
will first replace "$xyz_xxxx_xxxx" with the content of a variable named "xyz_xxxx_xxxx" (which most probably will not exist so that it evaluates to "", the empty string) and therefore search for a file named "v.txt". Whereas:
(notice the single quotes) will look for a file named exactly this: "v$xyz_xxxx_xxxx.txt".
If "$xyz" is a variable and you want to use that as the changing part of an otherwise fixed filename then this code snippet is for you:
This will search for a file name "vsome$thing_xxxx_xxxx.txt". Because of the braces around "xyz" the shell knows that only this (and not the rest of the string) is the name of the variable. Notice the double quotes: you should habitually double-quote every use of any variable - ever and always! (There are only very few exceptions to this rule of thumb.) This way blanks (yes, filename can contain blanks) will not break your script.
hey there
im a bit stuck on executing commands that include the special character '?'. can someone recommend a way on how i would be able to execute it?? i thought the glob function could be useful (still mite be) but upon entering the command
'ls pars?' it listed all the files in the... (1 Reply)
Hi ,
I am doing invert grep using -v but the string contain "/" which break the grep command and it do not skip the lines with "/" on it.
Diffu.txt
========
1159c1159
< <td align="right" valign="middle" class="paddingRight2px" id="featureListItemChannelButton7466">
---
> <td... (1 Reply)
Hi,
I am trying to unload file from a database. Which contains few lines with the character below. Rest of the data was unloaded appropriately.
a) What does this below character means?
b) How can i remove it,
I already have sed '/^$/d'
c) Will this effect the file by any means... (4 Replies)
Hi,
In the shell script, i need to remove the special charater "\" with "\\". For example, i need to replace "D:\FXT\ABC.TXT" with "D:\\FXT\\ABC.TXT".
However, when trying to do something like , i get the below error :-
-->echo "D:\FXT\ABC.TXT" | sed -e 's#\#\\#g'
sed: 0602-404 Function... (7 Replies)
I have below line in a unix file, I want to delete one character after "Â".
20091020.Non-Agency CMO Daily Trade Recap Â~V Hybrids
The result should be :
20091020.Non-Agency CMO Daily Trade Recap  Hybrids
i dont want to use "~V" anywhere in the sed command or any other command, just remove... (1 Reply)
I'm having issue capturing a value from file.list with a multiple spaces in a variable $i, tried various options like using double quotes, no quotes, single quotes, curly braces but to no avail.
cat file.list
aaa test bbb
ccc test ddd
eee test fff
for i in `cat file.list`
do
echo "$i";... (2 Replies)
Hi ,
I have input file like below
Hi this is "vinoth".
Hi happy to work with 'unix'
USA(united states of America)
My script variables are below :
Dquote=Ộ
Squote=&#$567
Obrac=&^986
Cbrac=&^745
I want to read the variables in my SED command to replace the double quote,single... (9 Replies)
When editing a file, vi displays a special character as ^L. Can you tell me the escaped character to be used in awk? And can that escaped character be used in a regexp in both sed and awk? (7 Replies)
Hello Folks,
Need to bisect strings based on a subset.
Below works good.
echo /a/b/c/d | awk -F"/c/d$" '{print $1}'
/a/b
However, it goes awry with special characters.
echo /a/b/c+/d | awk -F"/c+/d$" '{print $1}'
/a/b/c+/d
Desired output:
/a/b
Escaping the special characters... (11 Replies)
Hi,
on ksh
What does the following do?
grep -v "toolbox" $home_oracle/.profile >$home_oracle/.profile.$$ Thanks.
Please use CODE tags as required by forum rules! (3 Replies)
Discussion started by: big123456
3 Replies
LEARN ABOUT HPUX
read
read(1) General Commands Manual read(1)NAME
read - read a line from standard input
SYNOPSIS
var ...
DESCRIPTION
reads a single line from standard input. The line is split into fields as when processed by the shell (refer to shells in the first field
is assigned to the first variable var, the second field to the second variable var, and so forth. If there are more fields than there are
specified var operands, the remaining fields and their intervening separators are assigned to the last var. If there are more vars than
fields, the remaining vars are set to empty strings.
The setting of variables specified by the var operands affect the current shell execution environment.
Standard input to can be redirected from a text file.
Since affects the current shell execution environment, it is usually provided as a normal shell special (built-in) command. Thus, if it is
called in a subshell or separate utility execution environment similar to the following, it does not affect the shell variables in the
caller's environment:
Options
recognizes the following options:
Do not treat a backslash character in any special way.
Consider each backslash to be part of the input line.
Opperands
recognizes the following operands:
var The name of an existing or nonexisting shell variable.
EXTERNAL INFLUENCES
Environment Variables
determines the internal field separators used to delimit fields.
RETURN VALUE
exits with one of the following values:
0 Successful completion.
>0 End-of-file was detected or an error occurred.
EXAMPLES
Print a file with the first field of each line moved to the end of the line.
while read -r xx yy
do
printf "%s %s
" "$yy" "$xx"
done < input_file
SEE ALSO csh(1), ksh(1), sh(1), sh-posix(1).
STANDARDS CONFORMANCE read(1)