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1
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3answers
63 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
1answer
36 views

What is happening when a script encounters an error in one of the commands?

I used alien to convert an RPM to a .deb. I did NOT use alien's script conversion; I'm converting by hand. Indeed, the script did barf on some non-compatible syntax. My question is NOT about how to ...
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
326 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
387 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
3answers
919 views

Why does this incrementing for loop return a bad variable?

I'm trying to call this shell script from within the CLI of GRASS GIS: for (( day=5; day<367; day+5 )); do # commands that I've tested without a loop. done exit 0 returns Syntax error: Bad ...
0
votes
1answer
951 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 ...
11
votes
2answers
498 views

What is the difference between : and true?

In bash: $ type : : is a shell builtin $ type true true is a shell builtin Looks like they are the same, but they don't give the same system trace: $ strace : strace: :: command not found $ strace ...
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 ...
5
votes
2answers
532 views

Will I be able to build LFS using dash and mawk?

I decided that I want to learn more about Linux and try building LFS. I'm using Ubuntu 11.04 as host system and Ubuntu uses dash and mawk by default. I've changed mawk to gawk, but considering that ...
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?