10-17-2010
Help with command substitution in C program
Hi,
I want to know if there's a cleaner way for assigning output of a unix command to a variable in C program .
Example : I execute dirname fname and want the output to be assigned to a variable dname . Is it possible .
I knew u can redirect the output to a file and then reread assigning it , but ca it be done in a leaner better way . Thanks in advance .
10 More Discussions You Might Find Interesting
1. Shell Programming and Scripting
"Is there any substituation of last command or script syntax which can be used as a user. As far I know the "last" command is being used to display information about previous logins. A member of adm group or the user adm can execute it only.
Thanks in advance for your usual help.
Ghazi (6 Replies)
Discussion started by: ghazi
6 Replies
2. UNIX for Dummies Questions & Answers
Hi,
i want to write a script that executes a program (exec?) .
this program then requires a filename as input.
how do i give it this input in the script so the program will be complete run and close by the script.
e.g.
exec prog.exe
program then asks for filename
"enter filename:"... (1 Reply)
Discussion started by: tuathan
1 Replies
3. Shell Programming and Scripting
Hi,
What is the actual difference between these two? Why the following code works for process substitution and fails for command substitution?
while IFS= read -r line; do echo $line; done < <(cat file)executes successfully and display the contents of the file
But,
while IFS='\n' read -r... (3 Replies)
Discussion started by: royalibrahim
3 Replies
4. Shell Programming and Scripting
Hey, I was trying to figure out how to launch a program from the command line, and it works if you pass it a config file. I was thinking about writing a script to dynamically create the config file and pass it to the command using something like command substitution (so I don't actually have to... (3 Replies)
Discussion started by: bj0
3 Replies
5. UNIX for Dummies Questions & Answers
I know this script is crummy, but I was just messing around.. how do I get sed's insert command to allow variable expansion to show the filename?
#!/bin/bash
filename=`echo $0`
/usr/bin/sed '/#include/ {
i\
the filename is `$filename`
}' $1
exit 0 (8 Replies)
Discussion started by: glev2005
8 Replies
6. UNIX for Dummies Questions & Answers
Hey, guys!
Trying to research this is such a pain since the read command itself is a common word. Try searching "unix OR linux read command examples" or using the command substitution keyword. :eek:
So, I wanted to use a command statement similar to the following.
This is kinda taken... (2 Replies)
Discussion started by: ProGrammar
2 Replies
7. Shell Programming and Scripting
Hi,
I almost always use back quotes in scripts to assigin output of a command to a variable.
eg: file=`basename a/b/c/d/file`
year_mon=`date +%Y%m`
But the same can be achieved like:
file=$(basename a/b/c/d/file)
year_mon=$(date +%Y%m)
I would like to know if there is... (3 Replies)
Discussion started by: wanderingmind16
3 Replies
8. Shell Programming and Scripting
I have the following code:
strfuture=abcdefghi
ver=${strfuture:${count}:1}
mj7777_ver=${ver} start_mj7777_iteration
let count=count+1
When it is executed I get bad substitution. The same if I use
ver=${strfuture:$count:1}
mj7777_ver=${ver}... (6 Replies)
Discussion started by: Bruble
6 Replies
9. Shell Programming and Scripting
Oracle Linux 5.6, 64-bit
Given the following snippet
wrkvar=`sqlplus -s / as sysdba <<EOF
set echo off feedback off head off trimsp on
select count(*) from v\$parameter
where name in ('db_file_name_convert','log_file_name_convert')
and value is not null;
EOF`
echo wrkvar=$wrkvarProduces... (2 Replies)
Discussion started by: edstevens
2 Replies
10. Shell Programming and Scripting
Hi folks,
I totally dislike asking questions in forums but this one eats up to much of my time I need to spend on other topics.
I have a shell-script in which I call a terminal.
I want to invoke bash inside the terminal and print a message inside bash with aid of a here document.
See... (7 Replies)
Discussion started by: bluntroller
7 Replies
LEARN ABOUT DEBIAN
mcxalter
mcxalter(1) USER COMMANDS mcxalter(1)
NAME
mcxalter - various network transformations
SYNOPSIS
mcxalter [-imx <fname> (specify matrix input)] [-abc <fname> (specify label input)] [-tab <fname> (use tab file)] [-o <fname> (output)] [-tf
spec (apply tf-spec to input matrix)]
DESCRIPTION
This utility supplies various transformations of networks.
OPTIONS
-abc <fname> (label input)
The file name for input that is in label format.
-imx <fname> (input matrix)
The file name for input that is in mcl native matrix format.
-tab <fname> (use tab file)
This option causes the output to be printed with the labels found in the tab file. With -abc this option will, additionally, construct a
graph only on the labels found in the tab file. If this option is used in conjunction with -imx the tab domain and the matrix domain are
required to be identical.
-tf <tf-spec> (transform input matrix values)
Transform the input matrix values according to the syntax described in mcxio(5).
-o fname (output file)
Output file.
AUTHOR
Stijn van Dongen.
SEE ALSO
mcxio(5), mcx(1), mcxsubs(1), and mclfamily(7) for an overview of all the documentation and the utilities in the mcl family.
mcxalter 12-068 8 Mar 2012 mcxalter(1)