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#ifndef shell_main_func
#define shell_main_func
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/wait.h>
#include <unistd.h>
#define LSH_RL_BUFSIZE 1024
char *lsh_read_line(void)
{
int bufsize = LSH_RL_BUFSIZE;
int position = 0;
char *buffer = malloc(sizeof(char) * bufsize);
int c;
if (!buffer) {
fprintf(stderr, "lsh: allocation error\n");
exit(EXIT_FAILURE);
}
while (1) {
// Read a character
c = getchar();
// If we hit EOF, replace it with a null character and return.
if (c == EOF || c == '\n') {
buffer[position] = '\0';
return buffer;
} else {
buffer[position] = c;
}
position++;
// If we have exceeded the buffer, reallocate.
if (position >= bufsize) {
bufsize += LSH_RL_BUFSIZE;
buffer = realloc(buffer, bufsize);
if (!buffer) {
fprintf(stderr, "lsh: allocation error\n");
exit(EXIT_FAILURE);
}
}
}
}
//this needs to be rewritten/moved for better memory management. eg not writing to getenv or a pointer to a string that must not be modified
//eg dont use token=some pointer
char *handle_vars(char *token){
token=&token[0];
if (token[0] == '$'){
token=&token[1];
if(getenv(token)){
token=getenv(token);
} else {
token="";
}
}
/*
if (token[0] == '~'){
token=&token[1];
char *orig = (char*)malloc(sizeof(char) * ( strlen(token) + strlen(getenv("HOME") + 1)));
strcpy(orig,token);
strcpy(token,getenv("home")) has a weird doubling memory thing i dont understand
strcpy(token,getenv("HOME"));
strcat(token,orig);
printf("TOK: %s\n\n",token);
free(orig);
}
*/
return token;
}
#define LSH_TOK_BUFSIZE 64
#define LSH_TOK_DELIM " \t\r\n\a"
char **lsh_split_line(char *line)
{
int bufsize = LSH_TOK_BUFSIZE, position = 0;
char **tokens = malloc(bufsize * sizeof(char*));
char *token;
if (!tokens) {
fprintf(stderr, "lsh: allocation error\n");
exit(EXIT_FAILURE);
}
token = strtok(line, LSH_TOK_DELIM);
while (token != NULL) {
token = handle_vars(token);
tokens[position] = token;
position++;
if (position >= bufsize) {
bufsize += LSH_TOK_BUFSIZE;
tokens = realloc(tokens, bufsize * sizeof(char*));
if (!tokens) {
fprintf(stderr, "lsh: allocation error\n");
exit(EXIT_FAILURE);
}
}
token = strtok(NULL, LSH_TOK_DELIM);
}
tokens[position] = NULL;
return tokens;
}
int lsh_launch(char **args)
{
pid_t pid, wpid;
int status;
pid = fork();
if (pid == 0) {
// Child process
if (execvp(args[0], args) == -1) {
perror("lsh");
}
exit(EXIT_FAILURE);
} else if (pid < 0) {
// Error forking
perror("lsh");
} else {
// Parent process
do {
wpid = waitpid(pid, &status, WUNTRACED);
} while (!WIFEXITED(status) && !WIFSIGNALED(status));
}
return 1;
}
#endif
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