You don't understand, what I gave was a beginner's example. Some completely foolish function that no sane person on the planet would expect to work! I can't believe you're actually offering alternatives. Everybody knows a filename can be made of ANY character except /. The whole purpose was to explain that one cannot sanely rely on ${var:+set} to tell if a variable is set because a variable can very well be set with null string. I can very well run a function calling :
The second argument is SET but it's null string.
Is it normal behavior for a shell script that terminates to terminate its parent shell when executed with the "." option?
For example, if I have the example script (we'll name it ex.sh):
#!/bin/sh
if
then
echo "Bye."
exit 2
fi
And I execute it like this:
>./ex.sh
It... (6 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
I am trying to find lines in a text file larger than 3 Gb that start with a given string. My command looks like this:
$ look "string" "/home/patrick/filename.txt"
However, this gives me the following message:
"look: /home/patrick/filename.txt: File too large"
So, I have two... (14 Replies)
I've posted about this before, but only recently narrowed the problem down to a specific cause.
Ok, first of all, the behavior:
It occurs when autocompletion brings up its list (not when there is only a single option). Basically, if I were to type, say,
cd ~/<TAB>
I would get something... (2 Replies)
Hi,
I'm trying to sort a text file "test":
S12
S_S12
S_S1_12
S15
S_N15
S_N1_15
By "sort test", I get:
S12
S15
S_N1_15
S_N15
S_S1_12
S_S12
It seems weird:
Comparing Line 2 and Line 3, it must be that '-' is bigger than '1'; however, comparing Line 3 and Line 4, it seems that... (3 Replies)
This really puzzles me. The following code gives me the error 'expr: syntax error' when I try to do multi-line comment using here document
<<EOF
echo "Sum is: `expr $1 + $2`"
EOF
Even if I explicitly comment out the line containing the expr using "#", the error message would still exist... (3 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Discussion started by: asjaiswal
2 Replies
LEARN ABOUT BSD
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)