Tagged Questions
1
vote
3answers
64 views
How to know which is the default script shell in Centos?
I'm using Centos 6 and after reading about different shells and dash implementasion as sh replacement in Debian, Ubuntu and Fedora, made up my mind to replace sh with dash as the script shell in ...
2
votes
2answers
66 views
Calling bash from sh (dash) with commands read from args, and “Unterminated quoted string”/“unexpected EOF”
Just thought I'd document this: I'm trying something very simple - set env variable in bash, and print it out:
$ bash -c "a=1; echo a$a;"
a
$ bash -c "a=1; echo a\$a;"
a1
Now I'd want this same ...
0
votes
2answers
128 views
Proper place to put shell prompt(PS1) when use sh/bash/zsh together
I'm using dash(sh) or bash or zsh. If possible, I would prefer to put in common place.
I want to put proper PS1 settings when I interactive with shell, so these situation should be considered
login ...
0
votes
1answer
226 views
Login script for bash not loading
I am very confused about the login script for bash. I have always used ~/.bash_profile to configure my bash shell. Now I am on a new system just as a user: I am not root. This system was originally ...
4
votes
2answers
328 views
Get line number in a Bourne shell script
I'd like to be able to print the current line number in a shell script. I know about the $LINENO variable in Bash shells, but it doesn't seem to exist in Bourne shells. Is there any other variable ...
6
votes
1answer
349 views
Are dash, ash and sh script 100% compatible?
I wanted to know whether scripts written for dash, ash, and sh are 100% compatible?
Are there any added features to dash or ash, or syntax change?
From what I heard, ash is a direct descendant of ...
2
votes
2answers
388 views
When sh is a symlink to bash or dash, bash limits itself to POSIX-compliance, so it should be 100% compatible with sh?
From Difference between bash and sh:
ABck to the question: If you have /bin/sh as a link to bash, then bash will not behave the same when called as /bin/sh as it does when called as /bin/bash. ...
5
votes
1answer
439 views
A couple arithmetic related commands, Dash, POSIX shell, sh, Increment
When pre/post incrementing a variable, in POSIX Shell, what is the difference between these two examples. They seem like they would have the same consequences, but would they be used differently? ...
3
votes
1answer
216 views
In a script, check if standard input comes from a file or pipe
I know this has been poorly covered previously, but those answers either lack explanation or don't apply.
Basically at some point my scripts needs check if a file is specified, if it was it will be ...
0
votes
1answer
952 views
How to pkill from a script?
How can I write a script that basically just runs pkill -HUP inetd? I want to restart inetd via a script so I can schedule it to run at a particular time. I tried to write it myself, but I'm getting a ...
3
votes
2answers
267 views
Getopts option processing, Is it possible to add a non hyphenated [FILE]?
I'm using getopts for all of my scripts that require advanced option parsing, and It's worked great with dash. I'm familiar with the standard basic getopts usage, consisting of [-x] and [-x OPTION]. ...
4
votes
2answers
276 views
Can I trace a dash script without modifying its source code?
I would like to trace a shell script for debugging purposes without having to modify its source code (e.g. change the shebang or insert a set -x at the beginning). It is a dpkg postinst script, so not ...
0
votes
1answer
297 views
POSIX and Bash, sh shorthand, for compound if statement
I prefer to do my sh commands in shorthand, And I prefer to be in POSIX. Truthfully, if the script can run on Dash, that is good enough. Which means using the test command [, not the extended [[.
I ...
1
vote
1answer
118 views
How does this bash function work?
I'm looking at this short example, and I don't see how this function works:
function EXT_COLOR () { echo -ne "\[\033[38;5;$1m\]"; }
AFAIK -ne stands for not equal. What are we comparing here? I ...
2
votes
4answers
1k views
Shell script error message
I am trying to learn shell scripting by reading linuxcommand.org. For some reason I keep getting the error "Not Found", even though it runs all the commands.
The error codes I get are:
...
4
votes
2answers
526 views
dash compatibility to bash
Wikipedia says that dash executes faster than bash. My question is, if I set /bin/sh to dash, will all scripts that use /bin/sh in their shebang line that was intended for bash work under dash?
