Sponsored Content
Top Forums Shell Programming and Scripting The "read" command misinterprets file names containing spaces Post 302588181 by LessNux on Saturday 7th of January 2012 09:42:51 AM
Old 01-07-2012
Quote:
Originally Posted by LessNux
The delimiter can be changed from space to other characters by setting $IFS. However, I would rather stick on space for delimiter, because all characters including all symbols seem to be legal for file names or path names on modern GUI OS's.


Even a LF (\n, 0x0A) can be in file names on GUI OS's. Though it may be silly to put LF's in file names, it can accidentally happen when one copies from text and pastes it to a file name.

I thought about setting the delimiter to a non-printable character that is really unusual, such as ETX (0x03), ACK (0x06). However, it would be difficult for the user to input such non-printable characters at the read's prompt. I would like to let the user enter file names as he/she would enter on command line.

I discourage any attempts that resort to IFS.

The real problem is that the "read" command does not understand quotes and backslashes as the shell does. What the "read" command has obtained needs to be re-parsed by correctly handling quotes and backslashes like the shell. Can you think about any technique for such re-parsing?
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

passing a list of dynamic names to a "PS" command in shell script?

Hi, I am new to shell script. This is my first post .I have written a small script which returns list of names starts with "ram" in /etc/passwd .Here is that:- #!/bin/ksh NAME_LIST="name_list.txt" cat /dev/null > $NAME_LIST evalcmd="cat /etc/passwd | grep "^ram?*" | cut -d: -f1" eval... (3 Replies)
Discussion started by: sachin.tendulka
3 Replies

2. Shell Programming and Scripting

How to remove "New line characters" and "spaces" at a time

Dear friends, following is the output of a script from which I want to remove spaces and new-line characters. Example:- Line1 abcdefghijklmnopqrstuvwxyz Line2 mnopqrstuvwxyzabcdefghijkl Line3 opqrstuvwxyzabcdefdefg Here in above example, at every starting line there is a “tab” &... (4 Replies)
Discussion started by: anushree.a
4 Replies

3. Shell Programming and Scripting

script to read a line with spaces bet " " and write to a file

Hi, I need a command in UNIX KSH below is the description... MAPPING DESCRIPTION ="Test Mapping for the calid inputs" ISVALID ="YES" NAME ="m_test_xml" OBJECTVERSION ="1" VERSIONNUMBER ="1" unix ksh command to read the DESCRIPTION and write to a file Test Mapping for the calid inputs... (3 Replies)
Discussion started by: perlamohan
3 Replies

4. Shell Programming and Scripting

read -p "prompt text" foo say "read: bad option(s)" in Bourne-Shell

Hallo, i need a Prompting read in my script: read -p "Enter your command: " command But i always get this Error: -p: is not an identifier When I run these in c-shell i get this error /usr/bin/read: read: bad option(s) How can I use a Prompt in the read command? (9 Replies)
Discussion started by: wiseguy
9 Replies

5. Shell Programming and Scripting

"read" command ignoring leading spaces

I have to read a file line by line, change it and then update the file. Problem is, when i read the file, "read" command ignores leading spaces. The file is a script which is indented in many places for clarity. How to i make "read" command read leading spaces as well. (3 Replies)
Discussion started by: vickylife
3 Replies

6. Shell Programming and Scripting

Compare file names and select correct elements to include in "for each loop"

Hi everyone, I`ll try to be most clear I can explaining my help request. I have 2 folders Folder A-->This folder receives files through FTP constantly Folder B-->The files from Folder A are unzipped and then processed in Folder B Sometimes Folder A doesn`t contain all... (2 Replies)
Discussion started by: cgkmal
2 Replies

7. Shell Programming and Scripting

awk command to replace ";" with "|" and ""|" at diferent places in line of file

Hi, I have line in input file as below: 3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL My expected output for line in the file must be : "1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL" Can someone... (7 Replies)
Discussion started by: shis100
7 Replies

8. UNIX for Dummies Questions & Answers

Unix "look" Command "File too large" Error Message

I am trying to find lines in a text file larger than 3 Gb that start with a given string. My command looks like this: $ look "string" "/home/patrick/filename.txt" However, this gives me the following message: "look: /home/patrick/filename.txt: File too large" So, I have two... (14 Replies)
Discussion started by: shishong
14 Replies

9. UNIX for Dummies Questions & Answers

Using "mailx" command to read "to" and "cc" email addreses from input file

How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address and column 3 contains “cc” e-mail address to include with same email. Sample input file, email.txt Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies

10. Shell Programming and Scripting

Bash script - Print an ascii file using specific font "Latin Modern Mono 12" "regular" "9"

Hello. System : opensuse leap 42.3 I have a bash script that build a text file. I would like the last command doing : print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt where : print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies
Text::ParseWords(3perl) 				 Perl Programmers Reference Guide				   Text::ParseWords(3perl)

NAME
Text::ParseWords - parse text into an array of tokens or array of arrays SYNOPSIS
use Text::ParseWords; @lists = nested_quotewords($delim, $keep, @lines); @words = quotewords($delim, $keep, @lines); @words = shellwords(@lines); @words = parse_line($delim, $keep, $line); @words = old_shellwords(@lines); # DEPRECATED! DESCRIPTION
The &nested_quotewords() and &quotewords() functions accept a delimiter (which can be a regular expression) and a list of lines and then breaks those lines up into a list of words ignoring delimiters that appear inside quotes. &quotewords() returns all of the tokens in a single long list, while &nested_quotewords() returns a list of token lists corresponding to the elements of @lines. &parse_line() does tokenizing on a single string. The &*quotewords() functions simply call &parse_line(), so if you're only splitting one line you can call &parse_line() directly and save a function call. The $keep argument is a boolean flag. If true, then the tokens are split on the specified delimiter, but all other characters (quotes, backslashes, etc.) are kept in the tokens. If $keep is false then the &*quotewords() functions remove all quotes and backslashes that are not themselves backslash-escaped or inside of single quotes (i.e., &quotewords() tries to interpret these characters just like the Bourne shell). NB: these semantics are significantly different from the original version of this module shipped with Perl 5.000 through 5.004. As an additional feature, $keep may be the keyword "delimiters" which causes the functions to preserve the delimiters in each string as tokens in the token lists, in addition to preserving quote and backslash characters. &shellwords() is written as a special case of &quotewords(), and it does token parsing with whitespace as a delimiter-- similar to most Unix shells. EXAMPLES
The sample program: use Text::ParseWords; @words = quotewords('s+', 0, q{this is "a test" of quotewords "for you}); $i = 0; foreach (@words) { print "$i: <$_> "; $i++; } produces: 0: <this> 1: <is> 2: <a test> 3: <of quotewords> 4: <"for> 5: <you> demonstrating: 0 a simple word 1 multiple spaces are skipped because of our $delim 2 use of quotes to include a space in a word 3 use of a backslash to include a space in a word 4 use of a backslash to remove the special meaning of a double-quote 5 another simple word (note the lack of effect of the backslashed double-quote) Replacing "quotewords('s+', 0, q{this is...})" with "shellwords(q{this is...})" is a simpler way to accomplish the same thing. AUTHORS
Maintainer: Alexandr Ciornii <alexchornyATgmail.com>. Previous maintainer: Hal Pomeranz <pomeranz@netcom.com>, 1994-1997 (Original author unknown). Much of the code for &parse_line() (including the primary regexp) from Joerk Behrends <jbehrends@multimediaproduzenten.de>. Examples section another documentation provided by John Heidemann <johnh@ISI.EDU> Bug reports, patches, and nagging provided by lots of folks-- thanks everybody! Special thanks to Michael Schwern <schwern@envirolink.org> for assuring me that a &nested_quotewords() would be useful, and to Jeff Friedl <jfriedl@yahoo-inc.com> for telling me not to worry about error-checking (sort of-- you had to be there). perl v5.14.2 2010-12-30 Text::ParseWords(3perl)
All times are GMT -4. The time now is 08:28 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy