I'm writing a shell script using #!/bin/bash instead of #!/bin/sh because of the substitution: ${!variable}, which won't work with sh. My main problem is the following (just a summarized example, the script is much more complex):
Thank you!
---------- Post updated at 02:00 PM ---------- Previous update was at 12:32 PM ----------
At least someone to tell me the POSIX alternative for ${!variable}, please:
Last edited by teresaejunior; 08-28-2010 at 02:12 PM..
Reason: You could paste this now in a terminal
I have this situation in my script (simplified):
A=C
C=10
I need to get number 10 using just A variable.
I tried with :
echo $`echo $A` - but i get $C string (i need number)
Thanks very much for any help! (1 Reply)
Is it possible with a bash variable to perform multiple substitution strings to one variable?
I have this variable:
echo $clock
TIMEZONE="US/Central"
What I would like to do with bash only it pull out just the "US" part of the variable.. which could be any number of countries.
this is... (6 Replies)
Hi all.
I'm trying to finish a bash script with the following elements:
ARRAY="blah $ITEM blah blah"
ARRAY="blah blah $ITEM blah bluh"
#ARRAY="...."
# ...the ARRAY elements represent a variable but defined
# syntax and they're all hard-coded in the script.
#(...)
ITEMS='1.0 2.3... (2 Replies)
Hi,
I need to embed a metatag to image files which contain qrcodes, i usually do this with exiv -M "set Exif.Image.DocumentName `zbarimg -q -Sdisable -Sqrcode.enable --raw image.tif`" image.tif
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I have one script calling another with a set of strings that includes white space. Script A calls Script B with these input strings: one two "th ree"
Script B pulls apart the arguments correctly:
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if I call it from within Script A like so:... (10 Replies)
Hi
I am setting the variables like this :
setenv MODULE1 modem5__3
setenv MODULE2 modem5__2
setenv MODULE3 modem_ctrl_1_1
setenv MODULE4 modem_1_0
setenv COUNT 10
I am having a bash script as shown below
################################################
#!/bin/bash
for ((... (5 Replies)
OK, I'm striving to abide by all the rules this time.
Here is a fragment of my windows10/cygwin64/bash script:
export BUPLOG=$(BackupRecords --log "$src")
robocopy $(BackupRecords -mrbd "$src" --path "$src") $(BackupRecords --appSwitches "$src") "$src" "$dst" $(BackupRecords --fileSwitches... (0 Replies)
OK, I'm striving to abide by all the rules this time.
Here is a fragment of my windows10/cygwin64/bash script:
export BUPLOG=$(BackupRecords --log "$src")
robocopy $(BackupRecords -mrbd "$src" --path "$src") $(BackupRecords --appSwitches "$src") "$src" "$dst" $(BackupRecords --fileSwitches... (15 Replies)
Discussion started by: siegfried
15 Replies
LEARN ABOUT MOJAVE
subst
subst(n) Tcl Built-In Commands subst(n)
__________________________________________________________________________________________________________________________________________________NAME
subst - Perform backslash, command, and variable substitutions
SYNOPSIS
subst ?-nobackslashes? ?-nocommands? ?-novariables? string
_________________________________________________________________DESCRIPTION
This command performs variable substitutions, command substitutions, and backslash substitutions on its string argument and returns the
fully-substituted result. The substitutions are performed in exactly the same way as for Tcl commands. As a result, the string argument
is actually substituted twice, once by the Tcl parser in the usual fashion for Tcl commands, and again by the subst command.
If any of the -nobackslashes, -nocommands, or -novariables are specified, then the corresponding substitutions are not performed. For
example, if -nocommands is specified, command substitution is not performed: open and close brackets are treated as ordinary characters
with no special interpretation.
Note that the substitution of one kind can include substitution of other kinds. For example, even when the -novariables option is speci-
fied, command substitution is performed without restriction. This means that any variable substitution necessary to complete the command
substitution will still take place. Likewise, any command substitution necessary to complete a variable substitution will take place, even
when -nocommands is specified. See the EXAMPLES below.
If an error occurs during substitution, then subst will return that error. If a break exception occurs during command or variable substi-
tution, the result of the whole substitution will be the string (as substituted) up to the start of the substitution that raised the excep-
tion. If a continue exception occurs during the evaluation of a command or variable substitution, an empty string will be substituted for
that entire command or variable substitution (as long as it is well-formed Tcl.) If a return exception occurs, or any other return code is
returned during command or variable substitution, then the returned value is substituted for that substitution. See the EXAMPLES below.
In this way, all exceptional return codes are "caught" by subst. The subst command itself will either return an error, or will complete
successfully.
EXAMPLES
When it performs its substitutions, subst does not give any special treatment to double quotes or curly braces (except within command sub-
stitutions) so the script
set a 44
subst {xyz {$a}}
returns "xyz {44}", not "xyz {$a}" and the script
set a "p} q {r"
subst {xyz {$a}}
returns "xyz {p} q {r}", not "xyz {p} q {r}".
When command substitution is performed, it includes any variable substitution necessary to evaluate the script.
set a 44
subst -novariables {$a [format $a]}
returns "$a 44", not "$a $a". Similarly, when variable substitution is performed, it includes any command substitution necessary to
retrieve the value of the variable.
proc b {} {return c}
array set a {c c [b] tricky}
subst -nocommands {[b] $a([b])}
returns "[b] c", not "[b] tricky".
The continue and break exceptions allow command substitutions to prevent substitution of the rest of the command substitution and the rest
of string respectively, giving script authors more options when processing text using subst. For example, the script
subst {abc,[break],def}
returns "abc,", not "abc,,def" and the script
subst {abc,[continue;expr {1+2}],def}
returns "abc,,def", not "abc,3,def".
Other exceptional return codes substitute the returned value
subst {abc,[return foo;expr {1+2}],def}
returns "abc,foo,def", not "abc,3,def" and
subst {abc,[return -code 10 foo;expr {1+2}],def}
also returns "abc,foo,def", not "abc,3,def".
SEE ALSO
Tcl(n), eval(n), break(n), continue(n)
KEYWORDS
backslash substitution, command substitution, variable substitution
Tcl 7.4 subst(n)