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loop
Post 8760 by rwb1959 on Wednesday 17th of October 2001 11:54:59 AM
10-17-2001
Well... I know Neo is going to bust my chops for this
but you did try somthing and you need a little
direction so here goes...
OK. The first thing you should do in all shell scripts is to
set up the execution environment. You do this by inserting
the following line as the very first line in your script
(without the comments)...
#!/bin/sh <- Bourne Shell (normally)
...or
#!/bin/ksh <- Korn Shell
...or
#!/bin/csh <- C Shell
...remember that $* expands to ALL the positional parameters.
You need to read each one into a variable...
for prog in $*
do
... now, each time through the loop, $prog contains the next
positional parameter. Next, you want to check $prog for
"ordinary file" AND "executable file"...
if [ -f $prog -a -x $prog ]
then
...
else
...
fi
...then end your "do/done" loop and exit
done
exit 0
...just FYI, it's good programming practice to return some
sort of value (0 = AOK, 255 = Error) although this is a personal
preference.
You can then run this script in the background...
myscript /bin/ls /usr/bin/stat /bin/df ./myprog &
...you get the picture.
but you did try somthing and you need a little
direction so here goes...
OK. The first thing you should do in all shell scripts is to
set up the execution environment. You do this by inserting
the following line as the very first line in your script
(without the comments)...
#!/bin/sh <- Bourne Shell (normally)
...or
#!/bin/ksh <- Korn Shell
...or
#!/bin/csh <- C Shell
...remember that $* expands to ALL the positional parameters.
You need to read each one into a variable...
for prog in $*
do
... now, each time through the loop, $prog contains the next
positional parameter. Next, you want to check $prog for
"ordinary file" AND "executable file"...
if [ -f $prog -a -x $prog ]
then
...
else
...
fi
...then end your "do/done" loop and exit
done
exit 0
...just FYI, it's good programming practice to return some
sort of value (0 = AOK, 255 = Error) although this is a personal
preference.
You can then run this script in the background...
myscript /bin/ls /usr/bin/stat /bin/df ./myprog &
...you get the picture.
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LEARN ABOUT SUNOS
env
env(1) User Commands env(1) NAME
env - set environment for command invocation SYNOPSIS
/usr/bin/env [-i | -] [name=value...] [ utility [ arg... ]] /usr/xpg4/bin/env [-i | -] [name=value...] [ utility [ arg... ]] DESCRIPTION
The env utility obtains the current environment, modifies it according to its arguments, then invokes the utility named by the utility op- erand with the modified environment. Optional arguments are passed to utility. If no utility operand is specified, the resulting environment is written to the standard output, with one name=value pair per line. /usr/bin If env executes commands with arguments, it uses the default shell /usr/bin/sh (see sh(1)). /usr/xpg4/bin If env executes commands with arguments, it uses /usr/xpg4/bin/sh (see ksh(1)). OPTIONS
The following options are supported: -i | - Ignores the environment that would otherwise be inherited from the current shell. Restricts the environment for utility to that specified by the arguments. OPERANDS
The following operands are supported: name=value Arguments of the form name=value modify the execution environment, and are placed into the inherited environment before utility is invoked. utility The name of the utility to be invoked. If utility names any of the special shell built-in utilities, the results are unde- fined. arg A string to pass as an argument for the invoked utility. EXAMPLES
Example 1: Invoking utilities with new PATH values The following utility: example% env -i PATH=/mybin mygrep xyz myfile invokes the utility mygrep with a new PATH value as the only entry in its environment. In this case, PATH is used to locate mygrep, which then must reside in /mybin. ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment variables that affect the execution of env: LANG, LC_ALL, LC_CTYPE, LC_MES- SAGES, and NLSPATH. PATH Determine the location of the utility. If PATH is specified as a name=value operand to env, the value given shall be used in the search for utility. EXIT STATUS
If utility is invoked, the exit status of env is the exit status of utility. Otherwise, the env utility returns one of the following exit values: 0 Successful completion. 1-125 An error occurred. 126 utility was found but could not be invoked. 127 utility could not be found. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: /usr/bin +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ /usr/xpg4/bin +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWxcu4 | +-----------------------------+-----------------------------+ |CSI |enabled | +-----------------------------+-----------------------------+ |Interface Stability |Standard | +-----------------------------+-----------------------------+ SEE ALSO
ksh(1), sh(1), exec(2), profile(4), attributes(5), environ(5), standards(5) SunOS 5.10 2 Jan 2002 env(1)