i am running my application in linux by providing inputs as command line. My input field contain an argument which contains ";"(semicolon) internally.(For example:123;434;5464).
This will be parsed using UTF8String encode and send.
But when i am using like this, in initial itself i am getting,
bash: 434: command not found
bash: 5464: command not found
And when i capture traffic the output contains only 123 instead 123;434;5464
But if i give without semicolon (Ex:123:434:5464),not getting any problem output coming properly as 123:434:5464
Point me how to give command line input by using semicolon as to come output. Is there any particular syntax to use while doing with semicolon.
I am running like below
./runASR.sh -ip 10.78.242.4 -port 3868 -sce 10.78.241.206 -id 85;167838865;1385433280
where -id field contain that value with issue.
; is treated an end of command character. So 123;456;5464 to bash is in fact 3 commands. To pass such meta-characters escape it with escape character \.
./command 123\;456\;5464
Or Just quote it with single quote (double quote evaluates the inner string) (Thanks Triplee, I forgot to mention this)
./command '123;456;5464'
Related
I am writing a bash script and trying to do error handling and sanitizing the supplied parameters of the script. The supplied parameters have the form of key/value pairs and are separated by the '&' for the purpose of API compatibility:
cluster=xyz&tenant=abcd1234&key1=value1&key2=value2
In the simplest form, just to print out the supplied parameter, this script is just two lines:
#!/bin/bash
echo "The supplied parameter"
echo "$1"
When calling the script with the parameters in single or double quotes, everything works as expected:
$./script.sh 'cluster=xyz&tenant=abcd1234&key1=value1&key2=value2'
The supplied parameters
cluster=xyz&tenant=abcd1234&key1=value1&key2=value2
$./script.sh "cluster=xyz&tenant=abcd1234&key1=value1&key2=value2"
The supplied parameters
cluster=xyz&tenant=abcd1234&key1=value1&key2=value2
However, if I don't single/double quote the string, it causes the script to hang:
$ ./script.sh cluster=xyz&tenant=abcd1234&key1=value1&key2=value2
[1] 1080
[2] 1081
[3] 1082
[2] Done tenant=abcd1234
[3]+ Done key1=value1
$ The supplied parameters
cluster=xyz
And above stays until I press ctrl+c.
My question - how to properly sanitize the string when it is NOT enclosed in single/double quotes and prevent the above from occurring?
Bash version - GNU bash, version 5.0.17(1)-release (x86_64-pc-linux-gnu)
Thanks.
Seems there are only two ways to deal with the problem
Option 1 - one parameter as a string, containing '&' signs
One needs to ensure that the supplied parameters string is enclosed in single or double-quotes.
Option 2 - get rid of '&' char entirely and interpret multiple supplied parameters
The script should be called with multiple key/value parameters separated by space:
./script.sh cluster=xyz tenant=abcd1234 key1=value1 key2=value2
My python script can take a series of bitwise operators as one of its arguments. They all work fine except for "=<<" which is roll left, and "=>>" which is roll right. I run my script like ./script.py -b +4,-4,=>>10,=<<1, where anything after -b can be any combination of similar operations. As soon as the terminal sees "<<" though, it just drops the cursor to a new line after the command and asks for more input instead of running the script. When it sees ">>", my script doesn't process the arguments correctly. I know it's because bash uses these characters for a specific purpose, but I'd like to get around it while still using "=>>" and "=<<" in my arguments for my script. Is there any way to do it without enclosing the argument in quotation marks?
Thank you for your help.
You should enclose the parameters that contain special symbols into single quotation marks (here, echo represents your script):
> echo '+4,-4,=>>10,=<<1'
+4,-4,=>>10,=<<1
Alternatively, save the parameters to a file (say, params.txt) and read them from the file onto the command line using the backticks:
> echo `cat params.txt`
+4,-4,=>>10,=<<1
Lastly, you can escape some offending symbols:
> echo +4,-4,=\>\>10,=\<\<1
+4,-4,=>>10,=<<1
I'm using the flag package to interpret flags entered at the command line.
I created a variable using
ptrString := flag.String("string", "", "A test string")
flat.Parse()
Then when I want to print it,
fmt.Println("You entered " + *ptrString)
If I enter something like -string=hello! as a command line argument, it prints "hello!"
If I enter something like -string=hello\Bob as a command line argument, it prints "helloBob"
Is there a recommended way to convert or interpret the flag argument to a string that doesn't remove the backslash? (This is being tested on Linux and OS X, if the shell is interfering...)
Characters that have special meaning in the shell need to be quoted or escaped. You can find complete list in the shell's man pages (under "Quoting" in man 1 bash).
In this case, you can either quote or escape the baskslash
-string=hello\\Bob
// or
-string='hello\Bob'
I want to get some data from a HTTP server. What it sends me depends on what I put in a POST request.
What I put in the INPUT_TEXT field is a sequence of words. When I run the following command, I get good looking output.
$ curl http://localhost:59125/process -d INPUT_TEXT="here are some words"
I want a bash script to take some string as a command line argument, and pass it appropriately to curl. The first thing I tried was to put the following in a script:
sentence=$1
command="curl http://localhost:59125/process -d INPUT_TEXT=\"${sentence}\""
$command
I then run the script like so:
$ ./script "here are some words"
But then I get a curl Couldn't resolve host error for each of "are", "some", and "words". It would seem that "here" got correctly treated as the INPUT_TEXT, but the rest of the words were then considered to be hosts, and not part of the option.
So I tried:
command=("curl" "http://localhost:59125/process" "-d" "INPUT_TEXT='$sentence'")
${command[#]}
I got the same output as the first script. I finally got what I wanted with:
result=$(curl http://localhost:59125/process -d INPUT_TEXT="${sentence}")
echo $result
I'm still unsure as to what the distinction is. In the first two cases, when I echoed out the contents of command, I get exactly what I input from the interactive Bash prompt, which had worked fine. What caused the difference?
The following will work:
command=("curl" "http://localhost:59125/process"
"-d" "INPUT_TEXT=$sentence")
"${command[#]}"
That has two changes from yours:
I removed the incorrect quotes around $sentence since you don't want to send quotes to the server (as far as I can see).
I put double-quotes around the use of "${command[#]}". Without the double quotes, the array's elements are concatenated with spaces between them and then the result is word-split. With double quotes, the individual array elements are used as individual words.
The second point is well-explained in the bash FAQ and a bunch of SO answers dealing with quotes.
The important thing to understand is that quotes only quote when a command is parsed. A quote which is a character in a variable is just a character; it is not reinterpreted when the value of the variable expanded. Whitespace in the variable is used for word-splitting if the variable expansion is unquoted; the fact that the whitespace was quoted in the the command which defined the variable is completely irrelevant. In this sense, bash is just the same as any other programming language.
I am trying to understand how
sed 's/\^\[/\o33/g;s/\[1G\[/\[27G\[/' /var/log/boot
worked and what the pieces mean. The man page I read just confused me more and I tried the info sai Id but had no idea how to work it! I'm pretty new to Linux. Debian is my first distro but seemed like a rather logical place to start as it is a root of many others and has been around a while so probably is doing stuff well and fairly standardized. I am running Wheezy 64 bit as fyi if needed.
The sed command is a stream editor, reading its file (or STDIN) for input, applying commands to the input, and presenting the results (if any) to the output (STDOUT).
The general syntax for sed is
sed [OPTIONS] COMMAND FILE
In the shell command you gave:
sed 's/\^\[/\o33/g;s/\[1G\[/\[27G\[/' /var/log/boot
the sed command is s/\^\[/\o33/g;s/\[1G\[/\[27G\[/' and /var/log/boot is the file.
The given sed command is actually two separate commands:
s/\^\[/\o33/g
s/\[1G\[/\[27G\[/
The intent of #1, the s (substitute) command, is to replace all occurrences of '^[' with an octal value of 033 (the ESC character). However, there is a mistake in this sed command. The proper bash syntax for an escaped octal code is \nnn, so the proper way for this sed command to have been written is:
s/\^\[/\033/g
Notice the trailing g after the replacement string? It means to perform a global replacement; without it, only the first occurrence would be changed.
The purpose of #2 is to replace all occurrences of the string \[1G\[ with \[27G\[. However, this command also has a mistake: a trailing g is needed to cause a global replacement. So, this second command needs to be written like this:
s/\[1G\[/\[27G\[/g
Finally, putting all this together, the two sed commands are applied across the contents of the /var/log/boot file, where the output has had all occurrences of ^[ converted into \033, and the strings \[1G\[ have been converted to \[27G\[.