Programming

// bashescape.c
#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
int safe_system(const char *strin)
{
  int m,pos=0;
  char bufout[512];

  for(m=0; (pos<511)&&(strin[m] != '\0'); m++)
  {
    char c=strin[m];
    if(!(isalnum(c) || isspace(c)))
    {
      bufout[pos++]='\\';
      if(pos >= 510) break;
    }

    bufout[pos++]=c;
  }

  fprintf(stderr,"system(\"%s\")\n",bufout);
  return(system(bufout));
}

int main(int argc, char *argv[])
{
  return(safe_system(argv[1]));
}

# cc bashescape.c -o bashescape
# ./bashescape "echo hello ; world"
system("echo hello \; world")
hello ; world
#

#include<stdio.h>
#include<stdlib.h>
#include <ctype.h>
int sysrun(char *command) {
int num;
int m,pos;
char str[80];
char process[39] = "/gers/test/adhoc/syscr/wpleca2unix.sh ";
num=0;
for(m=0; (m<36)&&(command[m] != '\0'); m++)
  {
    char c=command[m];
    if(!(isalnum(c) || isspace(c)))
    {
      return 0;
    }
  }
strcpy(str,process);
strncat(str,command,35);
num = system(str);
return num;
}

for(m=0; command[m]; m++) /* check the whole thing */
  {
    if(!(isalnum(command[m]) || isspace(command[m])))
    {
      return 0;  
    }
  }