Can't read to var in Bash - linux

I wrote a little Bash script and I'm having a problem while reading from the command line. I think its because I wrote the script on Windows. Here is the code:
read NEW_MODX_PROJECT
and the output of the debug mode
+ read $'NEW_MODX_PROJECT\r'
Finally here the error I get
': Ist kein gültiger Bezeichner.DX_PROJECT
I think in English it should mean "': is not a valid identifier.DX_PROJECT"
While writing it on Windows, it worked fine. I used console2 to test it which is using the sh.exe.

Your assertion is correct -- Windows uses CRLF line separators but Linux just uses a LF.
The reason for your strange error message is that while printing the name of your variable, it includes the carriage return as part of its name -- the terminal then jumps back to the first column to print the rest of the error message (which overwrites the beginning of the message with the end of it).
There are a set of utilities known as dos2unix and unix2dos which you can use to easily convert between formats, e.g.:
dos2unix myscript.sh
If you don't happen to have them, you can achieve the same using tr:
tr -d '\r' < myscript.sh > myscript-new.sh
Either will strip all the carriage returns and should un-confuse things.

Related

How do I pass ">>" or "<<" to my script without the terminal trying to interpret it as me either appending to something or getting stdin?

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

Concatenating string read from file with string literals creates jumbled output

My problem is that the result is jumbled. Consider this script:
#!/bin/bash
INPUT="filelist.txt"
i=0;
while read label
do
i=$[$i+1]
echo "HELLO${label}WORLD"
done <<< $'1\n2\n3\n4'
i=0;
while read label
do
i=$[$i+1]
echo "HELLO${label}WORLD"
done < "$INPUT"
filelist.txt
5
8
15
67
...
The first loop, with the immediate input (through something I believe is called a herestring (the <<< operator) gives the expected output
HELLO1WORLD
HELLO2WORLD
HELLO3WORLD
HELLO4WORLD
The second loop, which reads from the file, gives the following jumbled output:
WORLD5
WORLD8
WORLD15
WORLD67
I've tried echo $label: This works as expected in both cases, but the concatenation fails in the second case as described. Further, the exact same code works on my Win 7, git-bash environment. This issue is on OSX 10.7 Lion.
How to concatenate strings in bash |
Bash variables concatenation |
concat string in a shell script
Well, just as I was about to hit post, the solution hit me. Sharing here so someone else can find it - it took me 3 hours to debug this (despite being on SO for almost all that time) so I see value in addressing this specific (common) use case.
The problem is that filelist.txt was created in Windows. This means it has CRLF line endings, while OSX (like other Unix-like environments) expects LF only line endings. (See more here: Difference between CR LF, LF and CR line break types?)
I used the answer here to convert the file before consumption. Using sed I managed to replace only the final line's carriage return, so I stuck to known guns and went for the perl approach. Final script is below:
#!/bin/bash
INPUTFILE="filelist.txt"
INPUT=$(perl -pe 's/\r\n|\n|\r/\n/g' "$INPUTFILE")
i=0;
while read label
do
i=$[$i+1]
echo "HELLO${label}WORLD"
done <<< $'INPUT'
Question has been asked in a different form at Bash: Concatenating strings fails when read from certain files

Understanding sed

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\[.

syntax error near unexpected token ' - bash

I have a written a sample script on my Mac
#!/bin/bash
test() {
echo "Example"
}
test
exit 0
and this works fine by displaying Example
When I run this script on a RedHat machine, it says
syntax error near unexpected token '
I checked that bash is available using
cat /etc/shells
which bash shows /bin/bash
Did anyone come across the same issue ?
Thanks in advance !
It could be a file encoding issue.
I have encountered file type encoding issues when working on files between different operating systems and editors - in my case particularly between Linux and Windows systems.
I suggest checking your file's encoding to make sure it is suitable for the target linux environment. I guess an encoding issue is less likely given you are using a MAC than if you had used a Windows text editor, however I think file encoding is still worth considering.
--- EDIT (Add an actual solution as recommended by #Potatoswatter)
To demonstrate how file type encoding could be this issue, I copy/pasted your example script into Notepad in Windows (I don't have access to a Mac), then copied it to a linux machine and ran it:
jdt#cookielin01:~/windows> sh ./originalfile
./originalfile: line 2: syntax error near unexpected token `$'{\r''
'/originalfile: line 2: `test() {
In this case, Notepad saved the file with carriage returns and linefeeds, causing the error shown above. The \r indicates a carriage return (Linux systems terminate lines with linefeeds \n only).
On the linux machine, you could test this theory by running the following to strip carriage returns from the file, if they are present:
cat originalfile | tr -d "\r" > newfile
Then try to run the new file sh ./newfile . If this works, the issue was carriage returns as hidden characters.
Note: This is not an exact replication of your environment (I don't have access to a Mac), however it seems likely to me that the issue is that an editor, somewhere, saved carriage returns into the file.
--- /EDIT
To elaborate a little, operating systems and editors can have different file encoding defaults. Typically, applications and editors will influence the filetype encoding used, for instance, I think Microsoft Notepad and Notepad++ default to Windows-1252. There may be newline differences to consider too (In Windows environments, a carriage return and linefeed is often used to terminate lines in files, whilst in Linux and OSX, only a Linefeed is usually used).
A similar question and answer that references file encoding is here: bad character showing up in bash script execution
try something like
$ sudo apt-get install dos2unix
$ dos2unix offendingfile
Easy way to convert example.sh file to UNIX if you are working in Windows is to use NotePad++ (Edit>EOL Conversion>UNIX/OSX Format)
You can also set the default EOL in notepad++ (Settings>Preferences>New Document/Default Directory>select Unix/OSX under the Format box)
Thanks #jdt for your answer.
Following that, and since I keep having this issue with carriage return, I wrote that small script. Only run carriage_return and you'll be prompted for the file to "clean".
https://gist.github.com/kartonnade/44e9842ed15cf21a3700
alias carriage_return=remove_carriage_return
remove_carriage_return(){
# cygwin throws error like :
# syntax error near unexpected token `$'{\r''
# due to carriage return
# this function runs the following
# cat originalfile | tr -d "\r" > newfile
read -p "File to clean ? "
file_to_clean=$REPLY
temp_file_to_clean=$file_to_clean'_'
# file to clean => temporary clean file
remove_carriage_return_one='cat '$file_to_clean' | tr -d "\r" > '
remove_carriage_return_one=$remove_carriage_return_one$temp_file_to_clean
# temporary clean file => new clean file
remove_carriage_return_two='cat '$temp_file_to_clean' | tr -d "\r" > '
remove_carriage_return_two=$remove_carriage_return_two$file_to_clean
eval $remove_carriage_return_one
eval $remove_carriage_return_two
# remove temporary clean file
eval 'rm '$temp_file_to_clean
}
I want to add to the answer above is how to check if it is carriage return issue in Unix like environment (I tested in MacOS)
1) Using cat
cat -e my_file_name
If you see the lines ended with ^M$, then yes, it is the carriage return issue.
2) Find first line with carriage return character
grep -r $'\r' Grader.sh | head -1
3) Using vim
vim my_file_name
Then in vim, type
:set ff
If you see fileformat=dos, then the file is from a dos environment which contains a carriage return.
After finding out, you can use the above mentioned methods by other people to correct your file.
I had the same problem when i was working with armbian linux and Windows .
i was trying to coppy my codes from windows to armbian and when i run it this Error Pops Up. My problem Solved this way :
1- try to Coppy your files from windows using WinSCP .
2- make sure that your file name does not have () characters

Linux replace ^M$ with $ in csv

I have received a csv file from a ftp server which I am ingesting into a table.
While ingesting the file I am receiving the error "File was a truncated file"
The actual reason is the data in a file contains $ and ^M$ in end of the line.
e.g :
ACT_RUN_TM, PROG_RUN_TM, US_HE_DT*^M$*
"CONFIRMED","","3600"$
How can I remove these $ and ^M$ from end of the line using linux command.
The ultimately correct solution is to transfer the file from the FTP server in text mode rather than binary mode, which does the appropriate end-of-line conversion for you. Change your download scripts or FTP application configuration to enable text transfers to fix this in future.
Assuming this is a one-shot transfer and you have already downloaded the file and just want to fix it, you can use tr(1) to translate characters. So to remove all control-M characters from a file, you can pipe through tr -d '\r'. Or if you want to replace them with control-J instead – for example you would do this if the file came from a pre-OSX Mac system — do tr '\r' '\n'.
It's odd to see ^M as not-the-last character, but:
sed -e 's/^M*\$$//g' <badfile >goodfile
Or use "sed -i" to update in-place.
(Note that "^M" is entered on the command line by pressing CTRL-V CTRL_M).
Update: It's been established that the question is wrong as the "^M$" are not in the file but displayed with VI. He actually wants to change CRLF pairs to just LF.
sed -e 's/^M$//g' <badfile >goodfile

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