How do I source from a string and not from a file
This is how we usually source a file
// somename.tcl
proc someName {} {
# The {} above means a list of zero formal arguments
puts "Hello from inside someName"
}
I can source this from any other tcl file in the following way
//main.tcl
source "somename.tcl"
//call someName
someName
Instead of the above, i would like to read contents of somename.tcl into a string and source the string. I want the contents of the string to be sourced in the same process context.
Like below
//main.tcl
set filename "somename.tcl"
set f [open $filename]
set content [read $f]
# I want to source the content here
#How do i do it?
The source command does something very much like this internally:
# Reading phase
set f [open $filename]
try {
fconfigure $f -encoding $encoding -eofchar "\032"
set contents [read $f]
} finally {
close $f
}
# Evaluation phase
set oldScript [info script]
try {
info script $filename
eval $contents
} finally {
info script $oldScript
}
where $encoding defaults to what [encoding system] reports. Except it does it in C and has some extra complication for simple argument parsing, and has somewhat different error handling in regard to stack traces.
In the simple case, you can convert that down to:
set f [open $filename]
set contents [read $f]
close $f
eval $contents
The eval command is the key here: it evaluates a Tcl script in a string. It's not very often used in modern Tcl, but for something like this it is the command of choice.
If you put the code inside a procedure, you need to change the eval for uplevel 1 to have the correct semantics; source does not change the stack frame for you:
proc simpleSource {filename} {
set f [open $filename]
set contents [read $f]
close $f
uplevel 1 $contents
}
Related
I am trying to parse a CSV to check if one of the headers is present.
Sometimes I'd expect a fifth colomn with arbitraryHead
date time value result arbitraryHead
val1 d1 10 fail
val2 d2 15 norun
I was trying to read the first line then print it. But that is not working...
How can I read the first line and print all the headers?
set fh [open $csv_file r]
set data [list]
set line [gets $fh line]
lappend data [split $line ,]
close $fh
foreach x $data {
puts "$x\n"
}
When reading a CSV file, it's best to use the csv package in Tcllib, as that handles all the awkward edge cases in that format.
In particular, csv::split is especially useful (along with csv::join when creating a CSV file). Or the various functions that act as wrappers around it. Here's how you'd use it in your case
package require csv
set fh [open $csv_file r]
# Your data appears to be actually tab-separated, not comma-separated...
set data [csv::split [gets $fh] "\t"]
close $fh
foreach x $data {
puts "$x\n"
}
Your actual immediate bug was this:
set line [gets $fh line]
The two-argument form of gets writes the line it reads into the variable named in the second argument, and returns the length of line read (or -1 on failure to read a complete line, which can be useful in complex cases that aren't important here). You're then assigning that value to the same variable with set, losing the string that was written there. You should instead use one of the following (except that you should use a properly-tested package for reading CSV files):
gets $fh line
set line [gets $fh]
The one-argument form of gets returns the line it read, which can make it harder to distinguish errors but is highly convenient.
The simplest you can do is string match operation, just look for the desired header you wanted to check.
As requested in the following code I am checking "arbitraryHead"
set fh [open $csv_file r]
set contents [read $fh ]
foreach x $contents {
if {[string match "*arbitraryHead*" $x]} {
puts "HEAD FOUND"
}
}
close $fh
Hope this address your issue
I want to print character from the next line:
say :
when this variable dum=183 exists in file , then print the very next charater from next line.
Note : I am using tcl
Thanks,
This should help you get started.
The typical idioms for working with a file one line at a time are:
1) linewise reading:
set f [open thefile.txt]
while {[gets $f line] >= 0} {
# work with the line of text in "line"
}
close $f
2) block reading with line splitting:
set f [open thefile.txt]
set text [read $f]
close $f
set lines [split [string trim $text] \n]
foreach line $lines {
# work with the line of text in "line"
}
This can be simplified by using a package:
package require fileutil
::fileutil::foreachLine line thefile.txt {
# work with the line of text in "line"
}
Another way is to search and extract using a regular expression. This is the worst method as it is inflexible and very likely to be buggy in use.
set f [open thefile.txt]
set text [read $f]
close $f
# this regular expression is an example
if {[regexp {\ydum\y[^\n]*.(.)} $text -> thecharacter]} {
# the character you wanted should be in "thecharacter"
}
Documentation:
>= (operator),
close,
fileutil (package),
foreach,
gets,
if,
open,
package,
read,
regexp,
set,
split,
string,
while,
Syntax of Tcl regular expressions
i have to perform following operation..
copy file from one location to another
search a word in the given file
and move the file pointer to beginning of that line
place the data in that location which are copied from other file...
3 files are as follows:
C:\program Files(X86)\Route\*.tcl
C:\Sanity_Automation\Route\*.tcl
C:\Script.tcl
First i need to copy files from Route folder in Program Files to
Sanity_Automation\Route*.tcl
Then i need to search "CloseAllOutputFile keyword in
C:/Sanity_Automation/Route/SystemTest.tcl
once found, move cursor to the beginning of that line where "CloseAllOutputFile " keyword found.
and place data found on script.tcl to that location.
Firstly, that first "file" is actually a pattern. We need to expand that to a list of real filenames. We do that with glob.
# In braces because there are backslashes
set pattern {C:\Program Files(X86)\Route\*.tcl}
# De-fang the backslashes
set pattern [file normalize $pattern]
# Expand
set sourceFilenames [glob $pattern]
Then we want to copy them. We could do this with:
set target {C:\Sanity_Automation\Route\}
file copy {*}$sourceFilenames [file normalize $target]
But really we also want to build up a list of moved files so that we can process them in the next step. So we do this:
set target {C:\Sanity_Automation\Route\}
foreach f $sourceFilenames {
set t [file join $target [file tail $f]]
file copy $f $t
lappend targetFilenames $t
}
OK, now we're going to do the insertion processing. Let's start by getting the data to insert:
set f [open {C:\Script.tcl}]
set insertData [read $f]
close $f
Now, we want to go over each of the files, read them in, find where to do the insertion, actually do the insertion if we find the place, and then write the files back out. (You do text edits by read/modify-in-memory/write rather than trying to modify the file directly. Always.)
# Iterating over the filenames
foreach t $targetFilenames {
# Read in
set f [open $t]
set contents [read $f]
close $f
# Do the search (this is the easiest way!)
if {[regexp -indices -line {^.*CloseAllOutputFile} $contents where]} {
# Found it, so do the insert
set idx [lindex $where 0]
set before [string range $contents 0 [expr {$idx-1}]]
set after [string range $contents $idx end]
set contents $before$insertData$after
# We did the insert, so write back out
set f [open $t "w"]
puts -nonewline $f $contents
close $f
}
}
Normally, I'd do the modify as part of the copy, but we'll do it your way here.
Try this:
set sourceDir [file join / Files(x86) Route]
set destinationDir [file join / Sanity_Automation Route]
# Read the script to be inserted
set insertFnm [file join / Script.tcl]
set fil [open $insertFnm]
set insertData [read $fil]
close $fil
# Loop around all the Tcl scripts in the source directory
foreach inFnm [glob [file join $sourceDir *.tcl]] {
# Determine the name of the output file
set scriptName [file tail $inFnm]
set outFnm [file join $destinationDir $scriptName]
# Open source and destination files, for input and output respectively
set inFil [open $inFnm]
set outFil [open $outFnm w]
while {![eof $inFil]} {
set line [gets $inFil]
if {[string match *CloseAllOutputFile* $line]} {
puts $outFil $insertData
puts $outFil ""; # Ensure there's a newline at the end
# of the insertion
}
puts $outFil $line
}
# Close input and output files
close $inFil
close $outFil
}
It seems to work for me.
I have a file contain lines with path to the files. Sometimes a path contain SHELL environment variable and I want to check the file existence.
The following is my solution:
set fh [open "the_file_contain_path" "r"]
while {![eof $fh]} {
set line [gets $fh]
if {[regexp -- {\$\S+} $line]} {
catch {exec /usr/local/bin/tcsh -c "echo $line" } line
if {![file exists $line]} {
puts "ERROR: the file $line is not exists"
}
}
}
I sure there is more elegant solution without using
/usr/local/bin/tcsh -c
You can capture the variable name in the regexp command and do a lookup in Tcl's global env array. Also, your use of eof as the while condition means your loop will interate one time too many (see http://phaseit.net/claird/comp.lang.tcl/fmm.html#eof)
set fh [open "the_file_contain_path" "r"]
while {[gets $fh line] != -1} {
# this can handle "$FOO/bar/$BAZ"
if {[string first {$} $line] != -1} {
regsub -all {(\$)(\w+)} $line {\1::env(\2)} new
set line [subst -nocommand -nobackslashes $new]
}
if {![file exists $line]} {
puts "ERROR: the file $line does not exist"
}
}
First off, it's usually easier (for small files, say of no more than 1–2MB) to read in the whole file and split it into lines instead of using gets and eof in a while loop. (The split command is very fast.)
Secondly, to do the replacement you need the place in the string to replace, so you use regexp -indices. That does mean that you need to take a little more complex approach to doing the replacement, with string range and string replace to do some of the work. Assuming you're using Tcl 8.5…
set fh [open "the_file_contain_path" "r"]
foreach line [split [read $fh] "\n"] {
# Find a replacement while there are any to do
while {[regexp -indices {\$(\w+)} $line matchRange nameRange]} {
# Get what to replace with (without any errors, just like tcsh)
set replacement {}
catch {set replacement $::env([string range $line {*}$nameRange])}
# Do the replacement
set line [string replace $line {*}$matchRange $replacement]
}
# Your test on the result
if {![file exists $line]} {
puts "ERROR: the file $line is not exists"
}
}
TCL programs can read environment variables using the built-in global variable env. Read the line, look for $ followed by a name, look up $::env($name), and substitute it for the variable.
Using the shell for this is very bad if the file is supplied by untrusted users. What if they put ; rm * in the file? And if you're going to use a shell, you should at least use sh or bash, not tcsh.
I have a file in here which has multiple set statements. However I want to extract the lines of my interest. Can the following code help
set in [open filename r]
seek $in 0 start
while{ [gets $in line ] != -1} {
regexp (line to be extracted)
}
Other solution:
Instead of using gets I prefer using read function to read the whole contents of the file and then process those line by line. So we are in complete control of operation on file by having it as list of lines
set fileName [lindex $argv 0]
catch {set fptr [open $fileName r]} ;
set contents [read -nonewline $fptr] ;#Read the file contents
close $fptr ;#Close the file since it has been read now
set splitCont [split $contents "\n"] ;#Split the files contents on new line
foreach ele $splitCont {
if {[regexp {^set +(\S+) +(.*)} $ele -> name value]} {
puts "The name \"$name\" maps to the value \"$value\""
}
}
How to run this code:
say above code is saved in test.tcl
Then
tclsh test.tcl FileName
FileName is full path of file unless the file is in the same directory where the program is.
First, you don't need to seek to the beginning straight after opening a file for reading; that's where it starts.
Second, the pattern for reading a file is this:
set f [open $filename]
while {[gets $f line] > -1} {
# Process lines
if {[regexp {^set +(\S+) +(.*)} $line -> name value]} {
puts "The name \"$name\" maps to the value \"$value\""
}
}
close $f
OK, that's a very simple RE in the middle there (and for more complicated files you'll need several) but that's the general pattern. Note that, as usual for Tcl, the space after the while command word is important, as is the space between the while expression and the while body. For specific help with what RE to use for particular types of input data, ask further questions here on Stack Overflow.
Yet another solution:
as it looks like the source is a TCL script, create a new safe interpreter using interp which only has the set command exposed (and any others you need), hide all other commands and replace unknown to just skip anything unrecognised. source the input in this interpreter
Here is yet another solution: use the file scanning feature of Tclx. Please look up Tclx for more info. I like this solution for that you can have several scanmatch blocks.
package require Tclx
# Open a file, skip error checking for simplicity
set inputFile [open sample.tcl r]
# Scan the file
set scanHandle [scancontext create]
scanmatch $scanHandle {^\s*set} {
lassign $matchInfo(line) setCmd varName varValue; # parse the line
puts "$varName = $varValue"
}
scanfile $scanHandle $inputFile
close $inputFile
Yet another solution: use the grep command from the fileutil package:
package require fileutil
puts [lindex $argv 0]
set matchedLines [fileutil::grep {^\s*set} [lindex $argv 0]]
foreach line $matchedLines {
# Each line is in format: filename:line, for example
# sample.tcl:set foo bar
set varName [lindex $line 1]
set varValue [lindex $line 2]
puts "$varName = $varValue"
}
I've read your comments so far, and if I understand you correctly your input data file has 6 (or 9, depending which comment) data fields per line, separated by spaces. You want to use a regexp to parse them into 6 (or 9) arrays or lists, one per data field.
If so, I'd try something like this (using lists):
set f [open $filename]
while {[gets $f line] > -1} {
# Process lines
if {[regexp {(\S+) (\S+) (\S+) (\S+) (\S+) (\S+)} $line -> name source drain gate bulk inst]} {
lappend nameL $name
lappend sourceL $source
lappend drainL $drain
lappend gateL $gate
lappend bulkL $bulk
lappend instL $inst
}
}
close $f
Now you should have a set of 6 lists, one per field, with one entry in the list for each item in your input file. To access the i-th name, for example, you grab $nameL[$i].
If (as I suspect) your main goal is to get the parameters of the device whose name is "foo", you'd use a structure like this:
set name "foo"
set i [lsearch $nameL $name]
if {$i != -1} {
set source $sourceL[$i]
} else {
puts "item $name not found."
set source ''
# or set to 0, or whatever "not found" marker you like
}
set File [ open $fileName r ]
while { [ gets $File line ] >= 0 } {
regex {(set) ([a-zA-Z0-0]+) (.*)} $line str1 str2 str3 str4
#str2 contains "set";
#str3 contains variable to be set;
#str4 contains the value to be set;
close $File
}