When you run any shell script it spawns a new shell, so including an exit statement will have no effect, you will still be returned to the parent shell that you run it from (unless you "source" the script using . ./abc.sh).
im trying to teach my self bash shell scripting. i want to include command line arguments in my script i am writing for practice. when i run my script it dosnt make a difference what arguments there are, it just out puts the error message as if there were none. here is the check_opts () function in... (4 Replies)
Im a newbie to shell scripting - in fact you could even call me a Linux newbie, well, mabye not i started with CYGWIN a year ago... but i only just recently wiped the Windoze partition off my drive.
-Anyways, heres the script i have a problem with:
#!/bin/bash
#
#PeMPcoder
function... (2 Replies)
Hi Guys,
I am trying to alter a script for my company.
I need the start of it to go something like this.
User is asked to input 8 numbers
8 numbers are written to a txt file
***** ***** ***** txt file is read ***** *****
The text file gets read in between other files represented by... (2 Replies)
I am fairly new to Unix scripting. A need has come where I need to to read the first column of a tab delimited file. The first column will be an id number and so I would need to read the first column one by one and create another file with only unique id numbers. So for example, if I have the... (14 Replies)
I need to invoke a program on remote server using ssh in a shell script. In addition i would like to capture date/time and if there is any errors , then script should write to log file. can someone please help me out? (1 Reply)
HELP!My program ends after entering one choice---need help making it take multiple inputs,instead of terminating after displaying just one
#!/bin/bash# Crude address databaseclear # Clear the screen.echo " Contact List"echo " ------- ----"echo "Choose one of the following... (6 Replies)
So I'm trying to pass certain json elements as env vars and use them later on in a script.
Sample json:
JSON='{
"Element1": "file-123456",
"Element2": "Name, of, company written in, a very weird way",
"Element3": "path/to/some/file.txt",
}'
(part of the) script:
for s... (5 Replies)
In Bash shell - the ps -ef shows only the /bin/bash but the script name is not displayed ? Is there any way to get the script names for the process command ?
--- Post updated at 08:39 AM ---
in KSH (Korn Shell), my command output shows the script names but when run in the Bash Shell... (3 Replies)
Discussion started by: i4ismail
3 Replies
LEARN ABOUT CENTOS
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)