How to use a execvp-call to do "grep PATH"?

 
Thread Tools Search this Thread
Homework and Emergencies Homework & Coursework Questions How to use a execvp-call to do "grep PATH"?
# 1  
Old 10-22-2009
Problem solved! How to use a execvp-call to do "grep PATH"?

Hello!
I am learning how to use the function execvp. I have read through the UNIX manual.
I have a process. I run execvp and I command it to do “printenv”. It works fine.
Before I do the execvp-call I pipe STDOUT to go to a specific pipe. After that I restore STDOUT. I read that pipe in another process. I have tested it and it works.

Now in this other process I want to do execvp again and I want to command execvp to do “grep ...”.
I don't succeed in doing this.

Here is some of my code:
char* environment_variables_vector[60];
My function call is this: execvp ("grep", environment_variables_vector)

Environment_variables_vector have this format:
Position 0 is a pointer to the string “grep PATH”
Position 1 is a pointer to: A nulterminated string containing an environment variable
Position 2 is a pointer to: Another nulterminated string containing another environment variable
..etcetera, up to
Position 52 is a pointer to: Another nulterminated string containing another environment variable.

When I run the program it doesn't run the code after the execvp-call.

4. School (University) and Course Number:
Royal Technical Highschool, ID2206

Thanks for your help!

EDIT: Problem solved!

Anders Branderud
proofofaCreator.wordpress.com

Last edited by andersbranderud; 10-23-2009 at 06:45 AM..
# 2  
Old 10-30-2009
What was the issue ?
# 3  
Old 10-30-2009
Vbe wrote: "What was the issue ?"

My reply:
As I wrote,
"Now in this other process I want to do execvp again and I want to command execvp to do “grep …”.
I don’t succeed in doing this."

Why I didn't succeed in doing it was because my inparameters were not correct. After reading the manual pages more carefully and searching on google how others did the same, I solved the problem.

Last edited by pludi; 10-30-2009 at 07:33 AM.. Reason: removed self promotion
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

find . -path "*_nobackup*" -prune -iname "*.PDF" \( ! -name "*_nobackup.*" \)

These three finds worked as expected: $ find . -iname "*.PDF" $ find . -iname "*.PDF" \( ! -name "*_nobackup.*" \) $ find . -path "*_nobackup*" -prune -iname "*.PDF" They all returned the match: ./folder/file.pdf :b: This find returned no matches: $ find . -path "*_nobackup*" -prune... (3 Replies)
Discussion started by: wolfv
3 Replies

2. Shell Programming and Scripting

grep with "[" and "]" and "dot" within the search string

Hello. Following recommendations for one of my threads, this is working perfectly : #!/bin/bash CNT=$( grep -c -e "some text 1" -e "some text 2" -e "some text 3" "/tmp/log_file.txt" ) Now I need a grep success for some thing like : #!/bin/bash CNT=$( grep -c -e "some text_1... (4 Replies)
Discussion started by: jcdole
4 Replies

3. Shell Programming and Scripting

"find . -printf" without prepended "." path? Getting path to current working directory?

If I enter (simplified): find . -printf "%p\n" then all files in the output are prepended by a "." like ./local/share/test23.log How can achieve that a.) the leading "./" is omitted and/or b.) the full path to the current directory is inserted (enclosed by brackets and a blank)... (1 Reply)
Discussion started by: pstein
1 Replies

4. Shell Programming and Scripting

Problem with "find" and "grep" command

I want to list all files/lines which except those which contain the pattern ' /proc/' OR ' /sys/' (mind the leading blank). In a first approach I coded: find / -exec ls -ld {} | grep -v ' /proc/| /sys/' \; > /tmp/list.txt But this doesn't work. I got an error (under Ubuntu): grep:... (5 Replies)
Discussion started by: pstein
5 Replies

5. 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

6. Shell Programming and Scripting

ps -ef | grep "string1" "string2" " "string3"

Hi all, can any one suggest me the script to grep multiple strings from ps -ef pls correct the below script . its not working/ i want to print OK if all the below process are running in my solaris system. else i want to print NOT OK. bash-3.00$ ps -ef | grep blu lscpusr 48 42 ... (11 Replies)
Discussion started by: steve2216
11 Replies

7. AIX

xx=`date +"%a %b %d"`;rsh xxx grep "^$XX" zzz ?

AIX 4.2 I am trying to do an rsh grep to search for date records inside server logs by doing this : xx=`date +"%a %b %d"` rsh xxx grep "^$XX" zzz gives : grep: 0652-033 Cannot open Jun. grep: 0652-033 Cannot open 11. But if I do : xx=`date +"%a %b %d"` grep "^$XX" zzz it works... (2 Replies)
Discussion started by: Browser_ice
2 Replies

8. Shell Programming and Scripting

ls -laR | grep "^-" | awk '{print $9}'| grep "$.txt"

Hi, I don't know hot to make this command work: ls -laR | grep "^-" | awk '{print $9}'| grep "$.txt" It should return the list of file .txt It's important to search .txt at the end of the line, becouse some file name have "txt" in their name but have other extensions (13 Replies)
Discussion started by: DNAx86
13 Replies

9. UNIX for Dummies Questions & Answers

Explain the line "mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`"

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

10. Shell Programming and Scripting

grep to find content in between curly braces, "{" and "},"

problem String ~~~~~~~~~~~~~~~~~~ icecream= { smart peopleLink "good" LC "happy" , smartpeopleLink "dull" LC "sad" } aend = {smart vc4 eatr kalu} output needed ~~~~~~~~~~~~~~~~~~ smart peopleLink "good" LC "happy" , smartpeopleLink "dull" LC "sad" smart vc4... (4 Replies)
Discussion started by: keshav_rk
4 Replies
Login or Register to Ask a Question