Backslashes within backquoted command substitutions do not behave the same way they would outside of backqutoed command substitution even when the command is otherwise identical (in this case an echo with a double-quoted argument). The backslashes are seen/parsed/consumed by the shell before it even invokes the subshell. In this case, you are left with echo "\" and so you get the error that the closing quote is not found because it's being escaped in the subshell.
Do yourself a massive favor and abandon all use of this archaic and obsoleted form of command substitution. It's quirky and buggy. Use $(...) instead and you'll live longer.
The string=$(echo "\\") form will work as expected, even as the command within the parenthesis increases in complexity. The same cannot be said of `...`.
Hi,
I have a script which looks through an input file and takes data from the file to use within the script.
Everything works fine until the script reads the item \windows\directory\structure\ from the input file into a variable.
As unix sees the backslash as an escape character, the... (5 Replies)
Hi
I need the "\\hello" (without double quotes) to be written to a file.
echo "\\\\hello" >file is working under bash shell but not working under ksh shell (gives only one / in the output)
Please advise.
TIA
Prvn (4 Replies)
I have a line that contains backslashes in which I want sed to substitute text with variables.
The line;
\\s008\2033330user$
I want to change this in \\s008.ourschool.com\2033330user$
I now use this script:
USER=2033330user
sed 's/\\'"$USER"'/.ourschool.com\\'"$USER/"
This doesn't... (3 Replies)
Bit of a weird one i suppose, i want to use an echo inside an echo... For example...
i have a script that i want to use to take users input and create another script. Inside this script it creates it also needs to use echos...
echo "echo "hello"" >$file
echo "echo "goodbye"" >$file
... (3 Replies)
Hi I am getting absurd behavior of escape character in echos as followed:oinlcso003{arsadm} #: echo "\as shdd"
\as shdd
oinlcso003{arsadm} #: echo "Well, isn't that \"special\"?"
Well, isn't that "special"?
oinlcso003{arsadm} #: echo "Well, isn't that \special\?"
Well, isn't that \special\?... (3 Replies)
Hi there,
I found something very weird!
Should I report that as a bug or is it me misusing the command?
I've got a file with a backslash in its name.
I know it's a horrible policy but it's not me.
The file came from a mac computer because this is a backup server.
Anyway, when using... (8 Replies)
Hello All,
In a Bash Script I'm writing I have a section where I loop through a text file that was
outputted by another script. In the text file some of the strings in there are enclosed with
the BOLD "character sequences" (i.e. "\033But it's weird, because if I run this command:
echo -E... (12 Replies)
Let's say I have a text file called process.out that contains:
cn=long\, ann,cn=users
cn=doe\, john,cn=users
I need to have the following appended in the beginning
ldapdelete -h $OIDHOST
So the final output looks like:
ldapdelete -h $OIDHOST "cn=long\, ann,cn=users"
ldapdelete -h... (4 Replies)
Hi,
How do I input \ when I do a vi of my file ? I try to input the \ but it came out as @.
Appreciate any help. (4 Replies)
Discussion started by: snowfrost88
4 Replies
LEARN ABOUT OSX
getopt
GETOPT(1) BSD General Commands Manual GETOPT(1)NAME
getopt -- parse command options
SYNOPSIS
args=`getopt optstring $*` ; errcode=$?; set -- $args
DESCRIPTION
The getopt utility is used to break up options in command lines for easy parsing by shell procedures, and to check for legal options.
Optstring is a string of recognized option letters (see getopt(3)); if a letter is followed by a colon, the option is expected to have an
argument which may or may not be separated from it by white space. The special option '--' is used to delimit the end of the options. The
getopt utility will place '--' in the arguments at the end of the options, or recognize it if used explicitly. The shell arguments ($1 $2
...) are reset so that each option is preceded by a '-' and in its own shell argument; each option argument is also in its own shell argu-
ment.
EXAMPLES
The following code fragment shows how one might process the arguments for a command that can take the options -a and -b, and the option -o,
which requires an argument.
args=`getopt abo: $*`
# you should not use `getopt abo: "$@"` since that would parse
# the arguments differently from what the set command below does.
if [ $? != 0 ]
then
echo 'Usage: ...'
exit 2
fi
set -- $args
# You cannot use the set command with a backquoted getopt directly,
# since the exit code from getopt would be shadowed by those of set,
# which is zero by definition.
for i
do
case "$i"
in
-a|-b)
echo flag $i set; sflags="${i#-}$sflags";
shift;;
-o)
echo oarg is "'"$2"'"; oarg="$2"; shift;
shift;;
--)
shift; break;;
esac
done
echo single-char flags: "'"$sflags"'"
echo oarg is "'"$oarg"'"
This code will accept any of the following as equivalent:
cmd -aoarg file file
cmd -a -o arg file file
cmd -oarg -a file file
cmd -a -oarg -- file file
SEE ALSO sh(1), getopt(3)DIAGNOSTICS
The getopt utility prints an error message on the standard error output and exits with status > 0 when it encounters an option letter not
included in optstring.
HISTORY
Written by Henry Spencer, working from a Bell Labs manual page. Behavior believed identical to the Bell version. Example changed in FreeBSD
version 3.2 and 4.0.
BUGS
Whatever getopt(3) has.
Arguments containing white space or embedded shell metacharacters generally will not survive intact; this looks easy to fix but isn't. Peo-
ple trying to fix getopt or the example in this manpage should check the history of this file in FreeBSD.
The error message for an invalid option is identified as coming from getopt rather than from the shell procedure containing the invocation of
getopt; this again is hard to fix.
The precise best way to use the set command to set the arguments without disrupting the value(s) of shell options varies from one shell ver-
sion to another.
Each shellscript has to carry complex code to parse arguments halfway correcty (like the example presented here). A better getopt-like tool
would move much of the complexity into the tool and keep the client shell scripts simpler.
BSD April 3, 1999 BSD