03-22-2009
Quote:
Originally Posted by
Perderabo
command1 && command2
First, command1 is run. Then if it does an "exit 0" or equivalent, then command2 is run. If command1 reports that it failed, then we just stop.
Shells are written in C and they use system calls to do stuff. fork() and exec() are system calls. The exec() system call is the model for the exec shell command. I was referring to the system calls being invoked.
ok, that actually makes sense...
but what seems like art to you, is like cipher text to me...
please explain
radoulov's command...
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
hi, new to to forum...
i've been trying to create a script in tcsh but i'm having a problem with one thing...
the script has to keep log of it's input and output so i'm using
tee -a log | script | tee -a log
this keeps the logs as asked, but it gives me an extra empty prompt (not in the... (0 Replies)
Discussion started by: moseschrist
0 Replies
2. Shell Programming and Scripting
Hi,
Is there anyway to duplicate output without using tee?
Let me explain the problem.
We are use ssh to login to remote server and save output to a file using tee commands for auditing purposes. When we use vi editor in ssh session, letters get garbled and cant really use vi. Without tee it... (7 Replies)
Discussion started by: eagles1
7 Replies
3. Shell Programming and Scripting
Hi,
I would like to process, filter the same ASCII asynchronous live data stream in more than one pipe pipeline.
So the one pipeline should filter out some records using grep key word
and more than one pipes pipelines
each should grep for another key words, each set seperately for each... (5 Replies)
Discussion started by: jack2
5 Replies
4. Shell Programming and Scripting
I'm redirecting the output of a command to a logfile, however, if the user is on a terminal I would also like the output to be displayed on the screen.
tar tvf some_tarfile >Logfile
if the user is on a term then have the output to the Logfile and also be displayed on the screen at the same... (2 Replies)
Discussion started by: nck
2 Replies
5. Shell Programming and Scripting
Hi there
I have a script that runs but it outputs everything onto the screen instead of a file.
I've tried using the > outputfile.txt however all it does is dump the output to the screen and creates an outputfile.txt but doesn't put anything in that file.
Any help would be appreciated
... (6 Replies)
Discussion started by: kma07
6 Replies
6. Shell Programming and Scripting
Hi,
When I run the following command in terminal it works. The string TEST is appended to a file silently.
echo TEST | tee -a file.txt &>/dev/null
However, when I paste this same line to a file, say shell1.sh, and use bourne shell .
I run this file in terminal, ./shell1.sh.
However I... (1 Reply)
Discussion started by: shahanali
1 Replies
7. Shell Programming and Scripting
We have an application here that does some table queries and then prints the result on screen. I do not have the code of this application (which i will just call "queryCommand"), but what it does is that you call it with some parameters and it prints some info about the query and then the... (5 Replies)
Discussion started by: jolateh
5 Replies
8. UNIX for Dummies Questions & Answers
Hello i am trying to write a script that will redirect the output to a certain file. Here is the code so far:
#!/bin/bash
ps -e | sort | more > psfile
When I execute the script nothing happens since i assume the output was redirected to the file called psfile. When I try to look at the... (1 Reply)
Discussion started by: mfruiz34
1 Replies
9. Shell Programming and Scripting
Hi
I am making a script where i want to redirect the output of ls -l to a file
Example
#ls -l fil1.txt > /opt/temp/a.txt
ac: No such file or directory
I want to capture output of this command
like here output is
ac: No such file or directory
can anyone help (4 Replies)
Discussion started by: anish19
4 Replies
10. Shell Programming and Scripting
Hi all
I was wondering if there was a slicker way of doing this without the file -
awk '{print $2}' FS=":" "${FILE}" > "${TMPFILE}"
{
read M_GRP_ID || m_fail 1 "Error: Read failed 1 (${FUNCNAME})"
read M_GRP_WAIT || m_fail 1 "Error: Read failed 2 (${FUNCNAME})"
}... (6 Replies)
Discussion started by: steadyonabix
6 Replies
LEARN ABOUT XFREE86
regex
regex(1F) FMLI Commands regex(1F)
NAME
regex - match patterns against a string
SYNOPSIS
regex [-e] [ -v "string"] [ pattern template] ... pattern [template]
DESCRIPTION
The regex command takes a string from the standard input, and a list of pattern / template pairs, and runs regex() to compare the string
against each pattern until there is a match. When a match occurs, regex writes the corresponding template to the standard output and
returns TRUE. The last (or only) pattern does not need a template. If that is the pattern that matches the string, the function simply
returns TRUE. If no match is found, regex returns FALSE.
The argument pattern is a regular expression of the form described in regex(). In most cases, pattern should be enclosed in single quotes
to turn off special meanings of characters. Note that only the final pattern in the list may lack a template.
The argument template may contain the strings $m0 through $m9, which will be expanded to the part of pattern enclosed in ( ... )$0 through
( ... )$9 constructs (see examples below). Note that if you use this feature, you must be sure to enclose template in single quotes so
that FMLI does not expand $m0 through $m9 at parse time. This feature gives regex much of the power of cut(1), paste(1), and grep(1), and
some of the capabilities of sed(1). If there is no template, the default is $m0$m1$m2$m3$m4$m5$m6$m7$m8$m9.
OPTIONS
The following options are supported:
-e Evaluates the corresponding template and writes the result to the standard output.
-v "string" Uses string instead of the standard input to match against patterns.
EXAMPLES
Example 1: Cutting letters out of a string
To cut the 4th through 8th letters out of a string (this example will output strin and return TRUE):
`regex -v "my string is nice" '^.{3}(.{5})$0' '$m0'`
Example 2: Validating input in a form
In a form, to validate input to field 5 as an integer:
valid=`regex -v "$F5" '^[0-9]+$'`
Example 3: Translating an environment variable in a form
In a form, to translate an environment variable which contains one of the numbers 1, 2, 3, 4, 5 to the letters a, b, c, d, e:
value=`regex -v "$VAR1" 1 a 2 b 3 c 4 d 5 e '.*' 'Error'`
Note the use of the pattern '.*' to mean "anything else".
Example 4: Using backquoted expressions
In the example below, all three lines constitute a single backquoted expression. This expression, by itself, could be put in a menu defini-
tion file. Since backquoted expressions are expanded as they are parsed, and output from a backquoted expression (the cat command, in this
example) becomes part of the definition file being parsed, this expression would read /etc/passwd and make a dynamic menu of all the login
ids on the system.
`cat /etc/passwd | regex '^([^:]*)$0.*$' '
name=$m0
action=`message "$m0 is a user"`'`
DIAGNOSTICS
If none of the patterns match, regex returns FALSE, otherwise TRUE.
NOTES
Patterns and templates must often be enclosed in single quotes to turn off the special meanings of characters. Especially if you use the
$m0 through $m9 variables in the template, since FMLI will expand the variables (usually to "") before regex even sees them.
Single characters in character classes (inside []) must be listed before character ranges, otherwise they will not be recognized. For exam-
ple, [a-zA-Z_/] will not find underscores (_) or slashes (/), but [_/a-zA-Z] will.
The regular expressions accepted by regcmp differ slightly from other utilities (that is, sed, grep, awk, ed, and so forth).
regex with the -e option forces subsequent commands to be ignored. In other words, if a backquoted statement appears as follows:
`regex -e ...; command1; command2`
command1 and command2 would never be executed. However, dividing the expression into two:
`regex -e ...``command1; command2`
would yield the desired result.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO
awk(1), cut(1), grep(1), paste(1), sed(1), regcmp(3C), attributes(5)
SunOS 5.10 12 Jul 1999 regex(1F)