This is not at all straightforward. Could you explain more about a scenario where this could be useful? If your shell has an array variable type (bash and ksh do), perhaps you could use that (at the cost of losing classic Bourne compatibility).
Here's a stab at implementing it.
How exactly this is more convenient than simply having the file names in $1 $2 $3 etc is debatable, but if you need to do it multiple times in different directories, that might be a valid use case.
Note the use of eval to get a variable name with a numeric index.
Last edited by era; 04-20-2008 at 09:23 AM..
Reason: Stab at implementing this
I do a lot of command line scripting to capture data from files or other command output. I've checked in a number of Unix and scripting books but for the life of me I can't find out how to asign field data from nawk output into variables that I can manipulate later. For example, reading a two... (6 Replies)
What am I doing wrong? I was searching for the answer to assigning variables from output. I found this simple response
ls -l apply_want.m | read perms links owner group size mtime1 mtime2 mtime3 file
this should allow me to echo the variables
echo "$perms | $links | $owner | $group |... (2 Replies)
Hi all,
Currently, i have a log file seperated by 'tab' and each record starting with a new line. i managed to retrieve the column that i'm interested in. (source_ip_address: xxx.xxx.xxx.xxx).
example of awk output: '{ print $43 }' assuming the field is at column 43.
10.10.10.10... (4 Replies)
Trying to finish up my script that automates some video encoding work.
Situation: There is an MKV file to be transcoded.
Problem: MKVINFO will give a bunch of output about an MKV file, included in that output are two lines I am interested in:
| + Default duration: 41.708ms (23.976 fps... (9 Replies)
Im trying to read the awk output to two variables. In the below code i need to store the if part output to a variable (NEW) and else part output to another variable (BAD). Pls shed some light on this snippet or if there is any other way to achieve it wud be appreciated (only condition is it needs... (7 Replies)
Hi , I have below command to that outputs from variables..
command:
echo $INSTANCE $DATAB $status $TSLastBackup| awk '{printf("%-8s %-8s \t \n",$1,$2,$3,$4)}' | tee $LOGF
the ouput is now:
INSTANCE DATABSE BACKUP_STATUS BACKUPTIMESTAMP
------- -------- -------- ... (1 Reply)
Hi
I need to assign the ouput of a awk statement to two variables; below is a example of the txt file i have which I use awk against
sample file
testval,USA,loc2,testing02
testval1,GB,loc4,testing01
awk statement
awk -F , '{print $2,$3}'
USA loc2
GB loc4
I need a method where... (6 Replies)
Hi,
How to set as variable from sql output.
Query:
select aa.serial, ao.name from ann_amit aa JOIN ann_object ao on (aa.classid=ao.classid);
I got two values from aa.serial and ao.name, I wanna make two different variable for aa.serial and ao.name.
The value of aa.serial should be in... (2 Replies)
Hi All,
I have written a (bash) function which generates multiple files say file1 file2 file3
now I want to reduce the generation of these three files i.e. store the output of three files in variables, and generate the same results, in-order to avoid multiple creation of files
how is that... (7 Replies)
Discussion started by: sam@sam
7 Replies
LEARN ABOUT PHP
source
exec(1) User Commands exec(1)NAME
exec, eval, source - shell built-in functions to execute other commands
SYNOPSIS
sh
exec [argument...]
eval [argument...]
csh
exec command
eval argument...
source [-h] name
ksh
*exec [arg...]
*eval [arg...]
DESCRIPTION
sh
The exec command specified by the arguments is executed in place of this shell without creating a new process. Input/output arguments may
appear and, if no other arguments are given, cause the shell input/output to be modified.
The arguments to the eval built-in are read as input to the shell and the resulting command(s) executed.
csh
exec executes command in place of the current shell, which terminates.
eval reads its arguments as input to the shell and executes the resulting command(s). This is usually used to execute commands generated as
the result of command or variable substitution.
source reads commands from name. source commands may be nested, but if they are nested too deeply the shell may run out of file descrip-
tors. An error in a sourced file at any level terminates all nested source commands.
-h Place commands from the file name on the history list without executing them.
ksh
With the exec built-in, if arg is given, the command specified by the arguments is executed in place of this shell without creating a new
process. Input/output arguments may appear and affect the current process. If no arguments are given the effect of this command is to mod-
ify file descriptors as prescribed by the input/output redirection list. In this case, any file descriptor numbers greater than 2 that are
opened with this mechanism are closed when invoking another program.
The arguments to eval are read as input to the shell and the resulting command(s) executed.
On this man page, ksh(1) commands that are preceded by one or two * (asterisks) are treated specially in the following ways:
1. Variable assignment lists preceding the command remain in effect when the command completes.
2. I/O redirections are processed after variable assignments.
3. Errors cause a script that contains them to abort.
4. Words, following a command preceded by ** that are in the format of a variable assignment, are expanded with the same rules as a vari-
able assignment. This means that tilde substitution is performed after the = sign and word splitting and file name generation are not
performed.
EXIT STATUS
For ksh:
If command is not found, the exit status is 127. If command is found, but is not an executable utility, the exit status is 126. If a redi-
rection error occurs, the shell exits with a value in the range 1-125. Otherwise, exec returns a zero exit status.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO csh(1), ksh(1), sh(1), attributes(5)SunOS 5.10 17 Jul 2002 exec(1)