将参数从Shell脚本传递到C程序

Question

gcc (GCC) 4.7.2
GNU bash, version 4.2.37

Hello,

I have the following bash script that I want to pass string parameter to my c program. I tried using pipes but failed.

The c program will need to get an input from the shell script. I am not sure to to read in an input from a shell script.

My bash script is below.

#!/usr/bash

# About on any errors
set -e

RUN_WITH_VALGRIND=""

if [ "$1" == "valgrind" ]; then
    RUN_WITH_VALGRIND="valgrind"
    echo "START TESTING WITH VALGRIND"
fi

$RUN_WITH_VALGRIND ./c_program

echo "Hello" | ./c_program

And my sample c program is here:

char str_input[16];
printf("Get input: ");
scanf("%s", str_input);
printf("Input [ %s ]\n", str_input);

I am trying to get the scanf to read the input from the shell script.

Many thanks for any advice,

Answer 1

echo "Hello" | $RUN_WITH_VALGRIND ./c_program echo "Hello" | $RUN_WITH_VALGRIND ./c_program , it's that simple.

But in your script, c_program will run twice as you re-call it after the run_with_valgrind call (I don't know if its intend or not)

Answer 2

I like to use 'here docs' for that:

$RUN_WITH_VALGRIND ./c_program <<EOF
first
second
EOF

cf. http://tldp.org/LDP/abs/html/here-docs.html