Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Bash to ash port, character-matching problem
Operating Systems Linux Ubuntu Bash to ash port, character-matching problem Post 302910165 by Don Cragun on Tuesday 22nd of July 2014 10:48:37 PM
Old 07-22-2014
The bash shell provides lots of extensions above and beyond what the POSIX standards require. The ash shell doesn't provide nearly as many extensions. If you use the standard as your shell programming guide, you should get by OK. A straight translation (getting rid of bash extensions) for your script would be:
Code:
printf "Username:"
read _username
if [ "$_username" = "${_username%[^a-zA-Z0-9]*}" ]
then    echo "Valid"
else    echo "INVALID"
fi

If your system allows alphanumeric characters other than characters in the Portable Filename Character Set in user names, you might want:
Code:
printf "Username:"
read _username
if [ "$_username" = "${_username%[^[:album:]]*}" ]
then    echo "Valid"
else    echo "INVALID"
fi

 

10 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

character matching

Is there a way to pull out a character at a time from a work in unix, using a shell script? (1 Reply)
Discussion started by: Rukshan
1 Replies

2. UNIX for Dummies Questions & Answers

Matching character

Alright, I am stuck here. I have this variable that stores the word = HELLO and I have converted it it to ----- I have asked user to input one character at a time. SAy, if they enter E. Therefore, I need to search 2nd character and input E there. makes it -E--- (other checkings have been... (2 Replies)
Discussion started by: felixwhoals
2 Replies

3. Shell Programming and Scripting

Why generate "ash and bash" different output for same bash script?

Hi, For my bash script, terminal with bash is generate an OK output and program works right. already, terminal with ash have "line 48: syntax error: Bad substitution" output and program don't work. :confused: (0 Replies)
Discussion started by: s. murat
0 Replies

4. UNIX for Dummies Questions & Answers

Differences in BASH and ASH shells regarding if command?

Guys I now have a script that's working in a BASH environment, however one line doesn't appear to be working on an embedded device that has a busybox therefore ASH shell. I've googled but there's very little I can find regarding the ASH shell. In BASH the following line works... if ] ;... (6 Replies)
Discussion started by: Bashingaway
6 Replies

5. Shell Programming and Scripting

Ash shell character corrupted after gdbserver

I am trying to debug something using gdbserver, after the successful/YET REALLY SLOW debug session i see that the ash shell on the the target under debug is messed up. Probably because gdbserver tries to open the core file which is binary. How do i recover from it? Also any ideas to speed up... (2 Replies)
Discussion started by: dragonpoint
2 Replies

6. Shell Programming and Scripting

Bash Script to Ash (busybox) - Beginner

Hi All, I have a script that I wrote on a bash shell, I use it to sort files from a directory into various other directories. I have an variable set, which is an array of strings, I then check each file against the array and if it is in there the script sorts it into the correct folder. But... (5 Replies)
Discussion started by: sgtbobie
5 Replies

7. Ubuntu

Bash to Ash, errors and adjustments

I wrote Bash script and now I want to convert it to Ash. One headache is this function: do_adduser() { setaddprompt _arr_add=("Add manually" "Add via TXT" "return to main menu" "exit program") select add_action in "${_arr_add}" do case "$REPLY" in 1)... (7 Replies)
Discussion started by: fzivkovi
7 Replies

8. Ubuntu

Convert a bash to ash

hello everybody, i'm a beginner in ash and i want to convert this bash script to ash. this script send a xml file to a nagios server : #!/bin/bash PROGNAME=$(basename $0) RELEASE="Revision 0.3" print_release() { echo "$RELEASE" } print_usage() { echo "" echo "$PROGNAME... (6 Replies)
Discussion started by: mdijoux25
6 Replies

9. UNIX for Beginners Questions & Answers

Escape bash-special character in a bash string

Hi, I am new in bash scripting. In my work, I provide support to several users and when I connect to their computers I use the same admin and password, so I am trying to create a script that will only ask me for the IP address and then connect to the computer without having me to type the user... (5 Replies)
Discussion started by: arcoa05
5 Replies

10. UNIX for Beginners Questions & Answers

Bash script, find the next closed (not in use) port from some port range.

hi, i would like to create a bash script that check which port in my Linux server are closed (not in use) from a specific range, port range (3000-3010). the print output need to be only 1 port, and it will be nice if the output will be saved as a variable or in same file. my code is: ... (2 Replies)
Discussion started by: yossi
2 Replies

LEARN ABOUT FREEBSD

echo

ECHO(1) 						    BSD General Commands Manual 						   ECHO(1)

NAME

     echo -- write arguments to the standard output

SYNOPSIS

     echo [-n] [string ...]

DESCRIPTION

     The echo utility writes any specified operands, separated by single blank (' ') characters and followed by a newline ('
') character, to the
     standard output.

     The following option is available:

     -n    Do not print the trailing newline character.

     The end-of-options marker -- is not recognized and written literally.

     The newline may also be suppressed by appending 'c' to the end of the string, as is done by iBCS2 compatible systems.  Note that the -n
     option as well as the effect of 'c' are implementation-defined in IEEE Std 1003.1-2001 (``POSIX.1'') as amended by Cor. 1-2002.  For porta-
     bility, echo should only be used if the first argument does not start with a hyphen ('-') and does not contain any backslashes ('').  If
     this is not sufficient, printf(1) should be used.

     Most shells provide a builtin echo command which tends to differ from this utility in the treatment of options and backslashes.  Consult the
     builtin(1) manual page.

EXIT STATUS

     The echo utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

     builtin(1), csh(1), printf(1), sh(1)

STANDARDS

     The echo utility conforms to IEEE Std 1003.1-2001 (``POSIX.1'') as amended by Cor. 1-2002.

BSD
								 November 12, 2010							       BSD
All times are GMT -4. The time now is 04:46 AM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy