04-26-2006
how could i make a program mixed with many "|", "<" and ">"
I have written following code to do: ls -l | wc -w, it works:
but when there are not only a single "|", if there are more such as:
ls -l | sort -r | sort | sort -r, This program does not work, i want to know how could i deal with it when there are more "|", another situation is that, if it mixes "|" and "<" or ">", such as: cat < apa | wc | wc >h***, this is also complex, how could i deal with these? thank you very much
(The following is just for a single "|")
void pipeProcess(char *args1[], char *args2[]) {
int thepipe[2], pid;
if(pipe(thepipe) == -1)
oops("Can not get a pipe", 1);
/* Create a new process */
if((pid = fork()) == -1)
oops("Can not fork", 2);
if(pid >0) {/* This is parent process */
close(thepipe[1]); /* parent does not write to pipe */
if(dup2(thepipe[0], 0) == -1) /* let parent read interface attaches to stdin */
oops("Could not redirect stdin", 3);
close(thepipe[0]); /* close thepipe[0] interface because it has attached to stdin */
execvp(args2[0], args2);
oops(*args2, 4);
}
/* Child process executes av[1] and writesinto pipe */
close(thepipe[0]); /* Child does not read from pipe */
if(dup2(thepipe[1], 1) == -1)
oops("Could not redirect stdout", 4);
close(thepipe[1]);
execvp(args1[0], args1);
oops(*args1, 5);
}
9 More Discussions You Might Find Interesting
1. UNIX for Dummies Questions & Answers
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Discussion started by: Lokesha
4 Replies
2. Shell Programming and Scripting
hi All,
cat file_name | awk /^~/'{print $1","$2","$3","$4}' | sed -e 's/~//g'
Can this be done by using sed or awk alone (4 Replies)
Discussion started by: harshakusam
4 Replies
3. Shell Programming and Scripting
This is the script:
#!/bin/sh
if ; then rm -rf /usr/share/WallpaperChanger; fi
if ; then rm -rf /usr/bin/wallch; fi;
if ; then rm -rf /usr/share/applications/wallch.desktop; fi
if ; then rm -rf /usr/share/doc/wallch; fi
if ; then rm -rf /usr/share/man/man1/wallch.1.gz; fi
echo "Delete... (4 Replies)
Discussion started by: hakermania
4 Replies
4. Shell Programming and Scripting
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)
Discussion started by: shis100
7 Replies
5. Shell Programming and Scripting
logs:
"/home/abc/public_html/index.php"
"/home/abc/public_html/index.php"
"/home/xyz/public_html/index.php"
"/home/xyz/public_html/index.php"
"/home/xyz/public_html/index.php"
how to use "cut" or "awk" or "sed" to get the following result:
abc
abc
xyz
xyz
xyz (8 Replies)
Discussion started by: timmywong
8 Replies
6. Solaris
The system don't boot.
on the screen appears following:
press enter to maintenance (or type CTRL-D to continue)...I checked with format command.
... the slices "0-root","1-swap","2-backup" exist.
...the slises "3-var","6-usr" -unassigned. :( (16 Replies)
Discussion started by: wolfgang
16 Replies
7. UNIX for Dummies Questions & Answers
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
8. Shell Programming and Scripting
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Discussion started by: jcdole
1 Replies
9. AIX
Hi 2 all,
i have had AIX 7.2
:/# /usr/IBMAHS/bin/apachectl -v
Server version: Apache/2.4.12 (Unix)
Server built: May 25 2015 04:58:27
:/#:/# /usr/IBMAHS/bin/apachectl -M
Loaded Modules:
core_module (static)
so_module (static)
http_module (static)
mpm_worker_module (static)
... (3 Replies)
Discussion started by: penchev
3 Replies
LEARN ABOUT CENTOS
abrt-dump-oops
ABRT-DUMP-OOPS(1) ABRT Manual ABRT-DUMP-OOPS(1)
NAME
abrt-dump-oops - Extract oops from FILE (or standard input)
SYNOPSIS
abrt-dump-oops [-vusoxtm] [-d DIR]/[-D] [FILE]
DESCRIPTION
This tool creates problem directory from, updates problem directory with or prints oops extracted from FILE or standard input.
OPTIONS
-v, --verbose
Be more verbose. Can be given multiple times.
-s
Log to syslog
-o
Print found oopses on standard output
-d DIR
Create new problem directory in DIR for every oops found
-D
Same as -d DumpLocation, DumpLocation is specified in abrt.conf
-u PROBLEM
Save the extracted information in PROBLEM directory
-x
Make the problem directory world readable. Usable only with -d/-D
-t
Throttle problem directory creation to 1 per second
-m
Print search string(s) for abrt-watch-log to stdout and exit
SEE ALSO
abrt-watch-log(1), abrt.conf(5)
AUTHORS
o ABRT team
abrt 2.1.11 06/18/2014 ABRT-DUMP-OOPS(1)