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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <sys/wait.h>
#include "utils.h"
#include "exec.h"
#include "preproc.h"
char* get_var(char* varname, ShellState* shstate) {
MaybeStr maybe_varval = get_map_value(&shstate->shell_vars, varname);
if (maybe_varval.some == true) return maybe_varval.value;
return getenv(varname);
}
typedef struct {
QuotationMode qmode;
char* content;
} ExpandedChunk;
ExpandedChunk expand_chunk(Chunk chunk, ShellState* shstate) {
char* content;
if (chunk.qmode == SINGLE_Q || chunk.kind == LITERAL) {
if (chunk.qmode == SINGLE_Q && chunk.kind != LITERAL) exit(69);
content = chunk.as.literal_str;
} else if (chunk.kind == VAR_EXP) {
content = get_var(chunk.as.varname, shstate);
} else if (chunk.kind == REGION_EXP) {
exit(7); // Not supported yet; arithm
}
return (ExpandedChunk){.qmode = chunk.qmode, .content = content};
}
typedef struct {
StrVec complete_strs;
String active_str;
} WordSplittingGerm;
void add_expchunk(char* next_str, WordSplittingGerm* curr_res) {
for (int pos = 0; pos < strlen(next_str); pos++) {
if (next_str[pos] == ' ') {
push_to_StrVec(&curr_res->complete_strs, inner(&curr_res->active_str));
curr_res->active_str = make_String(256);
} else {
push_to_String(&curr_res->active_str, next_str[pos]);
}
}
}
StrVec expand_word(Word word, ShellState* state) {
WordSplittingGerm curr_res = {.complete_strs = make_StrVec(256), .active_str = make_String(25)};
for (int i = 0; i < word.count; i++) {
Chunk curr_cunk = **get_from_Word(&word, i);
ExpandedChunk curr_exp = expand_chunk(curr_cunk, state);
switch (curr_exp.qmode) {
case UN_Q:
add_expchunk(curr_exp.content, &curr_res);
break;
case SINGLE_Q:
append_str_to_String(&curr_res.active_str, curr_exp.content);
break;
case DOUBLE_Q:
append_str_to_String(&curr_res.active_str, curr_exp.content);
}
}
if (curr_res.active_str.count > 0) {
push_to_StrVec(&curr_res.complete_strs, inner(&curr_res.active_str));
}
return curr_res.complete_strs;
}
void merge_strvecs(StrVec* target, StrVec* source) {
for (int i = 0; i < source->count; i++) {
push_to_StrVec(target, *get_from_StrVec(source, i));
}
}
char** make_cmd_args(Command command, ShellState* shstate) {
StrVec arg_str_vec = make_StrVec(256);
for (int i = 0; i < command.args.count; i++) {
Token arg_i = *get_from_TokenVec(&command.args, i);
StrVec expanded_i;
switch (arg_i.kind) {
case TOK_WORD:
expanded_i = expand_word(arg_i.as.word, shstate);
merge_strvecs(&arg_str_vec, &expanded_i);
break;
default:
exit(67);
}
}
int argcount = arg_str_vec.count;
char** arg_str_arr = malloc(sizeof(char*) * (argcount + 1));
for (int j = 0; j < argcount; j++) {
arg_str_arr[j] = *get_from_StrVec(&arg_str_vec, j);
}
arg_str_arr[argcount] = NULL;
return arg_str_arr;
}
typedef struct {
char** args;
int stdin_fd;
int stdout_fd;
IntVec child_close_fds;
IntVec parent_close_fds;
} ExecutableCommand;
void execute_command(ExecutableCommand cmd, int* pgid) {
pid_t pid = fork();
if (pid == 0) {
if (*pgid == -1) {
setpgid(0, 0);
} else {
setpgid(0, *pgid);
}
dup2(cmd.stdin_fd, STDIN_FILENO);
dup2(cmd.stdout_fd, STDOUT_FILENO);
for (int i = 0; i < cmd.child_close_fds.count; i++) {
close(*get_from_IntVec(&cmd.child_close_fds, i));
}
signal(SIGINT, SIG_DFL);
signal(SIGQUIT, SIG_DFL);
signal(SIGTSTP, SIG_DFL);
signal(SIGTTIN, SIG_DFL);
signal(SIGTTOU, SIG_DFL);
execvp(cmd.args[0], cmd.args);
exit(67);
}
if (*pgid == -1) {
setpgid(pid, pid);
*pgid = pid;
} else {
setpgid(pid, *pgid);
}
}
void run_pipeline(Pipeline pl, ShellState* shstate) {
signal(SIGTTIN, SIG_IGN);
signal(SIGTTOU, SIG_IGN);
int last_pipe_fd;
int pgid = -1;
for (int i = 0; i < pl.count; i++) {
PipelineElement elem = *get_from_Pipeline(&pl, i);
ExecutableCommand cmd = {.child_close_fds = make_IntVec(64), .parent_close_fds = make_IntVec(64)};
cmd.args = make_cmd_args(elem.cmd, shstate);
if (i == 0) {
cmd.stdin_fd = STDIN_FILENO;
} else {
cmd.stdin_fd = last_pipe_fd;
push_to_IntVec(&cmd.child_close_fds, last_pipe_fd);
push_to_IntVec(&cmd.parent_close_fds, last_pipe_fd);
}
if (elem.conn == CONN_PIPE) {
int pipe_fds[2];
pipe(pipe_fds);
cmd.stdout_fd = pipe_fds[1];
push_to_IntVec(&cmd.child_close_fds, pipe_fds[1]);
push_to_IntVec(&cmd.parent_close_fds, pipe_fds[1]);
last_pipe_fd = pipe_fds[0];
} else {
cmd.stdout_fd = STDOUT_FILENO;
}
execute_command(cmd, &pgid);
for (int j = 0; j < cmd.parent_close_fds.count; j++) {
close(*get_from_IntVec(&cmd.parent_close_fds, j));
}
}
tcsetpgrp(STDIN_FILENO, pgid);
while (waitpid(-pgid, NULL, 0) > 0);
tcsetpgrp(STDIN_FILENO, getpgrp());
}
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