Get a Variable Value from the Macro Symbol Table

Source: R/symtable.R

The symget function extracts the value of a single macro variable from the macro symbol table.

symget(name)

Arguments

name

The name of the macro variable as a quoted string, with no leading ampersand or trailing dot ("."). The leading ampersand will be added automatically by the function. This parameter is required.

Value

The value of the macro variable as a character string. If the variable name is not found, the function will return an NA.

See also

msource()

Other symtable: print.symtable(), symclear(), symput(), symtable()

Examples

library(macro)

# Get path to demo macro program
src <- system.file("extdata/Demo3.R", package = "macro")

# Display source code
# - This is the macro input code
cd <- readLines(src)
cat(paste(cd, "\n"))
# #% Determine appropriate data path
# #%if ("&env." == "prod")
#   #%let pth <- /projects/prod/data
# #%else
#   #%let pth <- /projects/dev/data
# #%end

# Set environment variable using symput()
symput("env", "prod")

# Macro Execute Source Code
# - set clear to FALSE to so "env" value is not removed
msource(src, echo = FALSE, clear = FALSE)

# View "pth" macro variable
res <- symget("pth")

# View results
# - Path is set to the "prod" value
res
# [1] "/projects/prod/data"