Compiling C++-code without a file

Question

I\'m trying to compile some C++ code using your standard g++ compiler. However, rather than compiling from a file:

main.cpp:

#include 

        

Answer 1

On Unix you can automate all process creating C/C++ programs by usage shell.

1.Create file (example run_c.sh)

2.Paste code to this file

#!/bin/bash

# Generate random filename
RANDOM_FILENAME=`cat /dev/urandom | tr -dc 'A-Za-z0-9' | fold -w 20 | head -n 1`
RANDOM_FILENAME=_$RANDOM_FILENAME
readonly RANDOM_FILENAME

# random filename for a C file
RANDOM_FILENAME_C=$RANDOM_FILENAME.c
readonly RANDOM_FILENAME

# catch stdin as code
CODE=$1

# names headers of the C standart language
declare -a C_STANDART_LIBRARY=('stdio' 'errno' 'assert' 'math' 'stdarg' 'stdbool' 'stdlib' 'string' 'time')

# create the C file
touch $RANDOM_FILENAME_C

# write a first line to the file
printf '// Compile C code from stdin\n\n' >> $RANDOM_FILENAME_C

# make include all headers to the file
for header in "${C_STANDART_LIBRARY[@]}"
do
    printf '#include <%s.h>\n' $header >> $RANDOM_FILENAME_C
done

# make include all headers to the file
printf "\nint main(int argc, char *argv[]) {\n" >> $RANDOM_FILENAME_C

# split the code from stdin by ';' to an array lines
IFS=';' read -r -a LINES_CODE <<< "$CODE"

# write line by line the code
for line in "${LINES_CODE[@]}"
do
    printf '%s;\n' "$line" | sed -e 's/^[[:space:]]//' | sed -e 's/^/\t/' >> $RANDOM_FILENAME_C
done

# write ending the function 'main'
printf "\treturn 0;\n}\n" >> $RANDOM_FILENAME_C

# uncomment for display the C code
# cat $RANDOM_FILENAME_C

# compile the file
gcc -Wall -std=c11 -o $RANDOM_FILENAME $RANDOM_FILENAME_C

# run programm if no errors
if [ -f "$RANDOM_FILENAME" ];
    then
    ./$RANDOM_FILENAME
fi

# rm the file with source code
rm $RANDOM_FILENAME_C
# rm the compliled file

if [ -f "$RANDOM_FILENAME" ];
    then
        rm $RANDOM_FILENAME
fi

3.Make this file as executable

$ chmod +x run_c.sh 
$ ls -l | grep run_c.sh 
-rwxr-xr-x 1 setivolkylany setivolkylany 1589 Dec 26 11:19 run_c.sh

Usage:

$ ./run_c.sh 'int a = 4; int b = 6; int c = a + b; printf("%d + %d = %d\n", a, b, c)'
4 + 6 = 10

$ ./run_c.sh 'puts("Worked");'
Worked

Testing environment

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 8.6 (jessie)
Release:    8.6
Codename:   jessie
$ uname -a
Linux localhost 3.16.0-4-amd64 #1 SMP Debian 3.16.36-1+deb8u2 (2016-10-19) x86_64 GNU/Linux

Inspired from http://django-notes.blogspot.com/2013/01/compiling-c-from-stdin.html and https://github.com/vgvassilev/cling