Ch /ˌsiːˈeɪtʃ/ is a cross-platform C and C++ interpreter.
Ch was originally designed by Dr. Harry H. Cheng as a scripting language for beginners to learn math, computing, numerics and programming in C/C++.
It is now provided by SoftIntegration, Inc. Ch is written in C and runs under Windows, Linux, Mac OS X and some versions of Unix. It supports C90 and major C99 features, but it does not support the full set of C++ features. C99 complex and VLA features are supported in Ch before they become C99 standard. Ch can also be run as a interactive shell to execute C statement, C script file, unix commands and Windows commands(under windows only).
Ch supports the 1999 ISO C Standard (C99) and C++ classes. It is a superset of C with C++ classes. C99 major features such as complex numbers, variable length arrays (VLAs), IEEE-754 floating-point arithmetic and generic mathematical functions are supported. Wide characters in Addendum 1 for C90 is also supported.
The following C++ features are available in Ch:
Ch supports classes in C++ with the following additional capabilities:
As a C/C++ interpreter, Ch can be used as a scripting engine for your applications. The pointer to array or variables can be passed and shared in both binary C space and ch scripting space. It extends your applications with a C compatible scripting language.
Ch is a C-compatible shell similar to C-shell (csh). It can be used as login shell. Ch has a built-in string type for automatic memory allocation and de-allocation. It supports shell alias, history, filename wildcarding, piping and iteration etc.
Ch has built-in 2D/3D graphical plotting features and computational arrays for numerical computing. A 2D linear equation of the form b = A*x can be written verbatim in Ch.
There are two ways to run Ch code. One is:
printf("Hello world!\n");
Another is:
#include <stdio.h> int main() { printf("Hello world!\n"); }
Ch also supports interactive shell command and C statements.
> int i, *p, **p2 // i is an integer, p pointer, p2 double pointer > i=10 // i is assigned value 10 10 > p=&i // p points to address of i 00D847C0 > *p // the memory pointed by p has value 10 10 > p2=&p // p2 points to address of p 00D84D30 > **p2 // the memory pointed by the pointer at p2 has value 10 10 >
#include <stdio.h> #include <array.h> int main() { array double A[2][3] = {1, 2, 3, 4, 5, 6}; array double B[3][2]; printf("A= \n%f \n", A+A); B = 2*transpose(A); printf("B= \n%f \n", B); }
The output is:
A= 2.000000 4.000000 6.000000 8.000000 10.000000 12.000000 B= 2.000000 8.000000 4.000000 10.000000 6.000000 12.000000
Find and compile all .c files into .o in the current directory for which the .o file is old or absent:
#!/bin/ch #include <sys/stat.h> struct stat cstat, ostat; string_t c, o; foreach (c; `find . -name "*.c"`) { o=`echo $c | sed 's/.c$/.o/'`; stat(o, &ostat); stat(c, &cstat); if (ostat.st_mtime > cstat.st_mtime) { echo "compiling $c to $o"; gcc -c -o "$o" "$c"; } }
To plot a sine wave:
#include <math.h> #include <chplot.h> int main() { int numpoints = 36; array double x[numpoints], y[numpoints]; linspace(x, 0, 360); // assign x with values from 0 to 360 linearly y = sin(x*M_PI/180); plotxy(x, y, "Ch plot", "xlabel", "ylabel"); }