// C Program

This code is supposed to handle commands like ls, df, who, wc, and their flags. This code works if there is zero or only one flag but breaks if there is two or more such as ls -l -a for example. when more than one flag is entered, perror is triggered saying there is a bad address. I am unsure how to change it so that it accepts more than one flag.

#include

#include

#include

#include

#include

#include

typedef struct param {

char *param;

struct param *next;

} pt;

typedef struct cmd_list {

char *cmd;

int param_count;

pt *param_list;

struct cmd_list *next;

} clt;

void execommands(clt *cmds) {

clt *cmd = cmds;

pid_t pid = fork();

switch(pid) {

case -1:

// error return break;

case 0: {

char ** rhp_argv = NULL;

char * rhp = NULL;

pt *temp = NULL;

int i = 1;

temp = cmd->param_list;

rhp = cmd->cmd;

// allocate memory for rhp_argv

if(0 != cmd->param_count)

rhp_argv = (char **) calloc((cmd->param_count+1), sizeof(char *));

// set first element to command rhp_argv[0] = rhp;

// add remaining parameters to rhp_argv

temp = cmd->param_list;

while(temp != NULL) {

rhp_argv[i] = strdup(temp->param);

i++;

temp = temp->next;

}

}

else {

rhp_argv = (char **) calloc(2, sizeof(char *));

rhp_argv[0] = rhp;

}

execvp(rhp_argv[0], rhp_argv);

// error exit

} default:

{

int status;

waitpid(pid, &status, 0);

break;

}

}

}