BSOD2600
13th October 2009 20:20 UTC

Extract & parse command line output
What is the best method for parsing the output from a commandline tool? If this was C#, I'd probably just use a regular expression...

Sample commandline output:

CLUSTER_NAME   STATUS   MASTER_HOST               ADMIN    HOSTS  SERVERS
trg7u4         ok       symph9               abcadmin       23       21
trg7demo       ok       foo                  abcadmin       12       11

I need to extract "trg7u4" and "abcadmin" from that spew. I'd use something like nsExec::ExecToStack to run the program. I've ran across the NSISpcre_plug-in for REGEX. Also found arrays plugin which could be another option.

Any other better/efficient methods to get the data I need?

BSOD2600
19th October 2009 05:46 UTC

No recommended methods for parsing commandline output eh?

MSG
19th October 2009 08:55 UTC

This can be done using only StrCpy, StrLen and StrCmp. Also, I think ExecToLog is what you're looking for, not ExecToStack.

BSOD2600
23rd October 2009 06:00 UTC

Originally posted by MSG
This can be done using only StrCpy, StrLen and StrCmp.

Hows that? The spacing and names of those fields change depending on the users setup.

MSG
23rd October 2009 07:11 UTC

I would start with searching for two spaces in a row. Then skip all spaces, and voila I'm at the beginning of the next column. Do this for x columns and you're at the ADMIN column. Similarly, reading the entry would simply be a matter of reading all data until the first double space. (Or the first space, if the data cannot contain spaces.)

BSOD2600
23rd October 2009 09:50 UTC

Ended up using a ghetto solution in conjunction with StrTok

    nsExec::ExecToStack /TIMEOUT=${EXECTIMEOUT} '"command"'
    Pop $0 # return value/error/timeout
    Pop $1 # printed text, up to ${NSIS_MAX_STRLEN}
        ; Need better way to skip to the 2nd line of the LSCLUSTERS command output...
        
        ;write COMMAND output to file to easily read/parse
        FileOpen $0 $PLUGINSDIR\command.log w        
        FileWrite $0 "$1"        
        FileClose $0
        
        ;re-open file we just wrote. skip to the 2nd line
        FileOpen $0 $PLUGINSDIR\command.log r
        FileRead $0 $1  ; headers
        FileRead $0 $2  ; first row, which should be the localhost details
        FileClose $0
        MessageBox MB_OK "command_2: $2"        
        ${StrTok} $5 "$2" " " "0" "1"   ;cluster name
        ${StrTok} $6 "$2" " " "2" "1"   ;cluster master
        ${StrTok} $7 "$2" " " "3" "1"   ;cluster admin
        MessageBox MB_OK "tok0: $5. tok2: $6. tok3: $7."
        
        StrLen $R1 $5 ;cluster name
        ${If} $R1 > 0
            StrCpy $Cluster_Name $5            
        ${EndIf}
        
        StrLen $R1 $6 ;cluster master
        ${If} $R1 > 0
            StrCpy $Cluster_Master $6
        ${EndIf}
        
        StrLen $R1 $7 ;cluster admin
        ${If} $R1 > 0
            StrCpy $Cluster_User $7
            !insertmacro INSTALLOPTIONS_WRITE "cluster_account.ini" "Field 1" "State" ".\$Cluster_User"
        ${EndIf}