implementing a bash shell

[kukluxklan]

hi all,
im tring to implement a bash shell with some operations like(pipe,redir ection etc).im using execvp system call to achieve this.im stuck at redirecting the outut of a command to a file.the output im getting for the follwoing code is "*** ERROR: exec failed\n".....n y help??????????? ????

#include  <stdio.h>
#include  <sys/types.h>
#include  <stdlib.h>
#include  <string.h>
#include  <fcntl.h>
void  parse(char *line, char **argv)
{
        while (*line != '\0')
        {
                while (*line == ' ' || *line == '\t' || *line == '\n')
                        *line++ = '\0';
                *argv++ = line;
                while (*line != '\0' && *line != ' ' &&
                                *line != '\t' && *line != '\n')
                        line++;
        }
        *argv = '\0';
}
 
 
main(void)
{
        char  line[1024];
        char  *argv[64];
        char **envp;
        char command[50][20];
        int inredir=0,outredir=0; //FLAGS FOR CHECKING WHETHER REDIRECTIONS EXIST OR NOT
        char in_redir[100],out_redir[100];
        while (1)
        {
                printf("Shell -> ");
                gets(line);
                printf("\n");
                parse(line, argv);
                if (strcmp(argv[0], "exit") == 0)
                        exit(0);
                //execute(argv);
                int i=0,j=0;
                while(argv[i])
                {
                        //printf("%s\n",argv[i]);
                        if(strcmp(argv[i],"<")==0)
                        {
                                inredir=1;
                                strcpy(in_redir,argv[++i]);
                        }
                        else if(strcmp(argv[i],">")==0)
                        {
                                outredir=1;
                                strcpy(out_redir,argv[++i]);
                        }
                        else
                                strcpy(command[j++],argv[i]);
                        i++;
                }
                strcpy(command[j],"\0");
                pid_t  pid;
                int    status,fd1,fd2;
                if ((pid = fork()) < 0)
                {
                        printf("*** ERROR: forking child process failed\n");
                        exit(1);
                }
                else if (pid == 0)
                {
                        if(inredir)
                        {
                                fd1 = open(in_redir, O_RDONLY);
                                if (fd1 < 0)
                                {
                                        perror("catf1f2: f1");
                                        exit(1);
                                }
 
                                if (dup2(fd1, 0) != 0)
                                {
                                        perror("catf1f2: dup2(f1, 0)");
                                        exit(1);
                                }
                                close(fd1);
                        }
                        if(outredir)
                        {
                                fd2 = open(out_redir, O_WRONLY | O_TRUNC | O_CREAT, 0644);
                                if (fd2 < 0)
                                {
                                        perror("catf1f2: f2");
                                        exit(2);
                                }
                                if (dup2(fd2, 1) != 1)
                                {
                                        perror("catf1f2: dup2(f2, 1)");
                                        exit(1);
                                }
                                close(fd2);
                        }
                        if (execvp(command[0],command))
                        {
                                printf("*** ERROR: exec failed\n");
                                exit(1);
                        }
                }
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                }
 

im using a gcc compiler on fc6...