Login or Register to Ask a Question and Join Our Community


UNIX for Dummies Questions & Answers

Meaning of "exec 9<name" in scripts

 
Thread Tools Search this Thread
Top Forums UNIX for Dummies Questions & Answers Meaning of "exec 9<name" in scripts
# 1  
Old 11-22-2013
Meaning of "exec 9<name" in scripts
I have found code like

Code:
exec 9<filename

a number of times when looking over commonly used scripts here. What all does this do? Sometimes the filename is simply a list, but seems to always have read/write/execute attributes for all. I think the "<" means to accept this as input, but don't know about the 9.

TIA
# 2  
Old 11-22-2013
It opens a file descriptor (9 in this case) for reading, from file filename.
This User Gave Thanks to Scott For This Post:
wbport
# 3  
Old 11-22-2013
Standard input is file number 0, standard output is file number 1, and standard error is file number 2. Any other number can be used for whatever purpose you want -- in this case, they attach a file to it.
This User Gave Thanks to Corona688 For This Post:
wbport
# 4  
Old 11-22-2013
And, somewhat further down the script, you might find a read -u 9 (bash) or similar to actually input values from that descriptor.
These 2 Users Gave Thanks to RudiC For This Post:
rbatte1 wbport
 
Login or Register to Ask a Question

Previous Thread | Next Thread

9 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Bash script - Print an ascii file using specific font "Latin Modern Mono 12" "regular" "9"

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

2. UNIX for Dummies Questions & Answers

What is the meaning of "-s" option in "if" statement?

Hi Guys, I'm sorry but I can't find answer for this, what is the meaning of -s option in "if" statement on unix scipting. Please see sample below: opath=/home/output for i in N1 N2 N3 N4 do echo $i if then grep $i $opath/N5_CRAI > $opath/N5_$i.crai chmod 777 $opath/N5_$i.crai ... (7 Replies)
Discussion started by: rymnd_12345
7 Replies

3. UNIX for Dummies Questions & Answers

Variable "##*", "% *" meaning

Hi, What means "##*", "% *" in a variable?? I have this in the script that i'm reading: ... read line echo $line echo ${line#* } echo ${line##* } echo ${line% * } ... The first print: DN: RCROOT ONRM_ROOT_MO SNW ONRM_ROOT_MO BSC BSCCC2 BTS ALTOHATILLONOR The second print:... (2 Replies)
Discussion started by: darocham
2 Replies

4. Shell Programming and Scripting

awk command to replace ";" with "|" and ""|" at diferent places in line of file

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

Meaning of "b" modifier in "sort" command

I need to sort the following file by the rhdiskpower devices in the last column: Total_MB Free_MB OS_MB Name Failgroup Library Label UDID Product Redund Path 1024 851 1024 OCRVOT1_0000 OCRVOT1_0000 System UNKNOWN ... (3 Replies)
Discussion started by: wjssj
3 Replies

6. UNIX for Dummies Questions & Answers

the meaning of "!:*" in "alias foo 'command\!:*' filename"

Hi: How can I remove my own post? Thanks. (2 Replies)
Discussion started by: phil518
2 Replies

7. UNIX for Dummies Questions & Answers

Using "find" and "-exec rm" ... Just no luck :(

Hi All, Ok, so I'm fairly new to Unix, but would like to think I'm grasping things fairly ok (Well until now ;) ), BUT with this one I'm going in circles ... LOL .. really can't work out why? So sorry for this post if it seems a little "dumb" .. But here goes. In short I'd like to achieve the... (55 Replies)
Discussion started by: Dean Rotherham
55 Replies

8. UNIX for Dummies Questions & Answers

Meaning of $var->{"@$row[0]"}=" "; ???

while (my $row = $sth->fetchrow_arrayref) { $var->{"@$row"}=" "; } Can anyone help me understanding above mentioned. i) As per my knowledge $row is taking ARRAY Refernce from the database ii) @$row is containing the value of 0th index of the array, testted the same. but I am not able... (0 Replies)
Discussion started by: jaigs_27
0 Replies

9. UNIX for Dummies Questions & Answers

No utpmx entry: you must exec "login" from lowest level "shell"

Hi I have installed solaris 10 on an intel machine. Logged in as root. In CDE, i open terminal session, type login alex (normal user account) and password and i get this message No utpmx entry: you must exec "login" from lowest level "shell" :confused: What i want is: open various... (0 Replies)
Discussion started by: peterpan
0 Replies
Login or Register to Ask a Question