[BASH] eval command not expanding variables as expected.
Hi Guys,
I wrote a collection of bash functions years ago and now need to use them again but
I'm getting some error messages when eval tries to expand the variables names.
I recollect that I used the shopt command to set one of the options but I can't quite
remember the command that I used. However, I may be wrong regarding the shopt
command.
Anyway, the function in question is:
Code:
function array_load
{
local IFS=$'\n'
eval "$1=( \$( < \"\${$2}\" ) )"
}
This is the output from the sh -x command:
Code:
+ declare -i __ITR__
+ declare -a __FILE_SQL__
+ declare -a __TEMP_SQL__
+ array_load __FILE_SQL__ __SRC__
+ local 'IFS=
'
+ eval '__FILE_SQL__=( $( < "${__SRC__}" ) )'
++ __FILE_SQL__=($( < "${__SRC__}" ))
/Users/Shared/#BASHLIB/type/array.bash: line 53: ~/djia.csv: No such file or directory
The __SRC__ variable contains a relative reference to a file i.e. ~/djia.csv but I've also
tried using an absolute reference from the root directory which also does not get found.
you can also read from a file into an associative array
Remember! Only on bash version 4.0.x and above.
We Apple users and probably others only have version 3.2.x so associative arrays are a none starter.
As the OP has not quoted his bash version nor the OS and HW in use then we can only assume he MIGHT have bash version 4.0.x[plus] available.
Just an observation...
This User Gave Thanks to wisecracker For This Post:
Location: Saint Paul, MN USA / BSD, CentOS, Debian, OS X, Solaris
Posts: 2,288
Thanks Given: 430
Thanked 480 Times in 395 Posts
Hi.
Quote:
Originally Posted by wisecracker
Hi nezabudka...
Remember! Only on bash version 4.0.x and above.
We Apple users and probably others only have version 3.2.x so associative arrays are a none starter.
As the OP has not quoted his bash version nor the OS and HW in use then we can only assume he MIGHT have bash version 4.0.x[plus] available.
Just an observation...
I think those of us who use macos may need to get used to zsh. Here is a demo zsh script that was run on Mojave, not using eval:
$ ./z1
Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Apple/BSD, Darwin 18.7.0, x86_64
Distribution : macOS 10.14.6 (18G103), Mojave
zsh 5.3
-----
Input file data1:
red=stop
green=go
yellow=caution
-----
Results:
Plain print:
caution stop go
Values:
caution stop go
Keys:
yellow red green
Both vertically:
yellow
caution
red
stop
green
go
I wrote a collection of bash functions years ago and now need to use them again but
I'm getting some error messages when eval tries to expand the variables names.
The problem is ~ is not being expanded. It turns out to be a little tricky to expand ~ but also avoid word separation on the path name (white spaces in you array source filename).
Try:
Code:
function array_load
{
local IFS=$'\n'
local ARR_FILE=$(eval echo ${!2})
eval "$1=( \$( < \"$ARR_FILE\" ) )"
}
These 2 Users Gave Thanks to Chubler_XL For This Post:
I pass an argument to bash as run. The first command in green executes as expected, however the second in blue fails as the $run does not expand. I tried to escape the variable with \ thinking the quotes were making the literal translation and also "${run}" but both did not work to expand the... (3 Replies)
My OS is Linux (kernel 4.08.something) and AIX (7100-04-01-1543), the used ksh versions are:
ksh88: Version M-11/16/88f (AIX)
ksh93: Version M 93t+ 2009-05-01 (AIX), Version M 93u (Linux)
When writing a parser for stanza files in ksh i encountered a rather strange behavior. Here is a... (4 Replies)
Hi Guys,
I have an issue with awk and variables. I have trawled the internet and forums but can't seem to get the exactt syntax I need.
I have tried using awk -v and all sorts of variations but I have hit a brick wall. I have spent a full day on this and am just going round in circles.
... (3 Replies)
Hello,
so i'm making a script, using dynamic variables and trying to expand them. So far it hasn't worked out too well so it seems that I need some help from you, the elite.
Example:
#!/bin/sh
counter=0
until (($counter>5))
counter2=1
until (($counter2>6)); do
if ;... (5 Replies)
Hi,
I need some direction with the following. The below code is semi-psuedo code which will hopefully make it easier to understand what I am trying to achieve:
for i in `echo ${testarray
}`
do
let c=c+1
eval "first$c=$i"
while... (4 Replies)
Hi,
The following code finds the line containing fruits in test.txt and replaces instances of apple with banana.
ed -s test.txt <<< $'/fruits/s/apple/banana/g\nw'
What I want to do is put variables in the place of fruits, apple and banana.
I have tried replacing ' with " to get... (2 Replies)
If have
var='$variable'
how can I expand $variable.
I have tried many thing like duble quotes/braces etc, but nothing worked.
I need the solution ASAP. (2 Replies)
I have a little script to help me manage a gallery of image files. It makes symbolic links to every file in and below the current directory, placing them in a target directory which is passed to the script as a parameter. Unfortunately, the script pukes when I pass a parameter that contains... (4 Replies)