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console.c
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console.c
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/* Implementation of simple command-line interface */
#include "console.h"
#include <ctype.h>
#include <fcntl.h>
#include <inttypes.h>
#include <limits.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include "report.h"
/* Some global values */
bool simulation = false;
static cmd_ptr cmd_list = NULL;
static param_ptr param_list = NULL;
static bool block_flag = false;
static bool prompt_flag = true;
/* Am I timing a command that has the console blocked? */
static bool block_timing = false;
/* Time of day */
static double first_time;
static double last_time;
/*
* Implement buffered I/O using variant of RIO package from CS:APP
* Must create stack of buffers to handle I/O with nested source commands.
*/
#define RIO_BUFSIZE 8192
typedef struct RIO_ELE rio_t, *rio_ptr;
struct RIO_ELE {
int fd; /* File descriptor */
int cnt; /* Unread bytes in internal buffer */
char *bufptr; /* Next unread byte in internal buffer */
char buf[RIO_BUFSIZE]; /* Internal buffer */
rio_ptr prev; /* Next element in stack */
};
static rio_ptr buf_stack;
static char linebuf[RIO_BUFSIZE];
/* Maximum file descriptor */
static int fd_max = 0;
/* Parameters */
static int err_limit = 5;
static int err_cnt = 0;
static bool echo = 0;
static bool quit_flag = false;
static char *prompt = "cmd> ";
static bool has_infile = false;
/* Optional function to call as part of exit process */
/* Maximum number of quit functions */
#define MAXQUIT 10
static cmd_function quit_helpers[MAXQUIT];
static int quit_helper_cnt = 0;
static bool do_quit_cmd(int argc, char *argv[]);
static bool do_help_cmd(int argc, char *argv[]);
static bool do_option_cmd(int argc, char *argv[]);
static bool do_source_cmd(int argc, char *argv[]);
static bool do_log_cmd(int argc, char *argv[]);
static bool do_time_cmd(int argc, char *argv[]);
static bool do_comment_cmd(int argc, char *argv[]);
static void init_in();
static bool push_file(char *fname);
static void pop_file();
static bool interpret_cmda(int argc, char *argv[]);
/* Initialize interpreter */
void init_cmd()
{
cmd_list = NULL;
param_list = NULL;
err_cnt = 0;
quit_flag = false;
add_cmd("help", do_help_cmd, " | Show documentation");
add_cmd("option", do_option_cmd,
" [name val] | Display or set options");
add_cmd("quit", do_quit_cmd, " | Exit program");
add_cmd("source", do_source_cmd,
" file | Read commands from source file");
add_cmd("log", do_log_cmd, " file | Copy output to file");
add_cmd("time", do_time_cmd, " cmd arg ... | Time command execution");
add_cmd("#", do_comment_cmd, " ... | Display comment");
add_param("simulation", (int *) &simulation, "Start/Stop simulation mode",
NULL);
add_param("verbose", &verblevel, "Verbosity level", NULL);
add_param("error", &err_limit, "Number of errors until exit", NULL);
add_param("echo", (int *) &echo, "Do/don't echo commands", NULL);
init_in();
init_time(&last_time);
first_time = last_time;
}
/* Add a new command */
void add_cmd(char *name, cmd_function operation, char *documentation)
{
cmd_ptr next_cmd = cmd_list;
cmd_ptr *last_loc = &cmd_list;
while (next_cmd && strcmp(name, next_cmd->name) > 0) {
last_loc = &next_cmd->next;
next_cmd = next_cmd->next;
}
cmd_ptr ele = (cmd_ptr) malloc_or_fail(sizeof(cmd_ele), "add_cmd");
ele->name = name;
ele->operation = operation;
ele->documentation = documentation;
ele->next = next_cmd;
*last_loc = ele;
}
/* Add a new parameter */
void add_param(char *name,
int *valp,
char *documentation,
setter_function setter)
{
param_ptr next_param = param_list;
param_ptr *last_loc = ¶m_list;
while (next_param && strcmp(name, next_param->name) > 0) {
last_loc = &next_param->next;
next_param = next_param->next;
}
param_ptr ele = (param_ptr) malloc_or_fail(sizeof(param_ele), "add_param");
ele->name = name;
ele->valp = valp;
ele->documentation = documentation;
ele->setter = setter;
ele->next = next_param;
*last_loc = ele;
}
/* Parse a string into a command line */
static char **parse_args(char *line, int *argcp)
{
/*
* Must first determine how many arguments there are.
* Replace all white space with null characters
*/
size_t len = strlen(line);
/* First copy into buffer with each substring null-terminated */
char *buf = malloc_or_fail(len + 1, "parse_args");
buf[len] = '\0';
char *src = line;
char *dst = buf;
bool skipping = true;
int c;
int argc = 0;
while ((c = *src++) != '\0') {
if (isspace(c)) {
if (!skipping) {
/* Hit end of word */
*dst++ = '\0';
skipping = true;
}
} else {
if (skipping) {
/* Hit start of new word */
argc++;
skipping = false;
}
*dst++ = c;
}
}
/* Now assemble into array of strings */
char **argv = calloc_or_fail(argc, sizeof(char *), "parse_args");
src = buf;
for (int i = 0; i < argc; i++) {
argv[i] = strsave_or_fail(src, "parse_args");
src += strlen(argv[i]) + 1;
}
free_block(buf, len + 1);
*argcp = argc;
return argv;
}
static void record_error()
{
err_cnt++;
if (err_cnt >= err_limit) {
report(1, "Error limit exceeded. Stopping command execution");
quit_flag = true;
}
}
/* Execute a command that has already been split into arguments */
static bool interpret_cmda(int argc, char *argv[])
{
if (argc == 0)
return true;
/* Try to find matching command */
cmd_ptr next_cmd = cmd_list;
bool ok = true;
while (next_cmd && strcmp(argv[0], next_cmd->name) != 0)
next_cmd = next_cmd->next;
if (next_cmd) {
ok = next_cmd->operation(argc, argv);
if (!ok)
record_error();
} else {
report(1, "Unknown command '%s'", argv[0]);
record_error();
ok = false;
}
return ok;
}
/* Execute a command from a command line */
static bool interpret_cmd(char *cmdline)
{
if (quit_flag)
return false;
#if RPT >= 6
report(6, "Interpreting command '%s'\n", cmdline);
#endif
int argc;
char **argv = parse_args(cmdline, &argc);
bool ok = interpret_cmda(argc, argv);
for (int i = 0; i < argc; i++)
free_string(argv[i]);
free_array(argv, argc, sizeof(char *));
return ok;
}
/* Set function to be executed as part of program exit */
void add_quit_helper(cmd_function qf)
{
if (quit_helper_cnt < MAXQUIT)
quit_helpers[quit_helper_cnt++] = qf;
else
report_event(MSG_FATAL, "Exceeded limit on quit helpers");
}
/* Turn echoing on/off */
void set_echo(bool on)
{
echo = on ? 1 : 0;
}
/* Built-in commands */
static bool do_quit_cmd(int argc, char *argv[])
{
cmd_ptr c = cmd_list;
bool ok = true;
while (c) {
cmd_ptr ele = c;
c = c->next;
free_block(ele, sizeof(cmd_ele));
}
param_ptr p = param_list;
while (p) {
param_ptr ele = p;
p = p->next;
free_block(ele, sizeof(param_ele));
}
while (buf_stack)
pop_file();
for (int i = 0; i < quit_helper_cnt; i++) {
ok = ok && quit_helpers[i](argc, argv);
}
quit_flag = true;
return ok;
}
static bool do_help_cmd(int argc, char *argv[])
{
cmd_ptr clist = cmd_list;
report(1, "Commands:", argv[0]);
while (clist) {
report(1, "\t%s\t%s", clist->name, clist->documentation);
clist = clist->next;
}
param_ptr plist = param_list;
report(1, "Options:");
while (plist) {
report(1, "\t%s\t%d\t%s", plist->name, *plist->valp,
plist->documentation);
plist = plist->next;
}
return true;
}
static bool do_comment_cmd(int argc, char *argv[])
{
if (echo)
return true;
int i;
for (i = 0; i < argc - 1; i++)
report_noreturn(1, "%s ", argv[i]);
if (i < argc)
report(1, "%s", argv[i]);
return true;
}
/* Extract integer from text and store at loc */
bool get_int(char *vname, int *loc)
{
char *end = NULL;
long int v = strtol(vname, &end, 0);
if (v == LONG_MIN || *end != '\0')
return false;
*loc = (int) v;
return true;
}
static bool do_option_cmd(int argc, char *argv[])
{
if (argc == 1) {
param_ptr plist = param_list;
report(1, "Options:");
while (plist) {
report(1, "\t%s\t%d\t%s", plist->name, *plist->valp,
plist->documentation);
plist = plist->next;
}
return true;
}
for (int i = 1; i < argc; i++) {
char *name = argv[i];
int value = 0;
bool found = false;
/* Get value from next argument */
if (i + 1 >= argc) {
report(1, "No value given for parameter %s", name);
return false;
} else if (!get_int(argv[++i], &value)) {
report(1, "Cannot parse '%s' as integer", argv[i]);
return false;
}
/* Find parameter in list */
param_ptr plist = param_list;
while (!found && plist) {
if (strcmp(plist->name, name) == 0) {
int oldval = *plist->valp;
*plist->valp = value;
if (plist->setter)
plist->setter(oldval);
found = true;
} else
plist = plist->next;
}
/* Didn't find parameter */
if (!found) {
report(1, "Unknown parameter '%s'", name);
return false;
}
}
return true;
}
static bool do_source_cmd(int argc, char *argv[])
{
if (argc < 2) {
report(1, "No source file given");
return false;
}
if (!push_file(argv[1])) {
report(1, "Could not open source file '%s'", argv[1]);
return false;
}
return true;
}
static bool do_log_cmd(int argc, char *argv[])
{
if (argc < 2) {
report(1, "No log file given");
return false;
}
bool result = set_logfile(argv[1]);
if (!result)
report(1, "Couldn't open log file '%s'", argv[1]);
return result;
}
static bool do_time_cmd(int argc, char *argv[])
{
double delta = delta_time(&last_time);
bool ok = true;
if (argc <= 1) {
double elapsed = last_time - first_time;
report(1, "Elapsed time = %.3f, Delta time = %.3f", elapsed, delta);
} else {
ok = interpret_cmda(argc - 1, argv + 1);
if (block_flag) {
block_timing = true;
} else {
delta = delta_time(&last_time);
report(1, "Delta time = %.3f", delta);
}
}
return ok;
}
/* Create new buffer for named file.
* Name == NULL for stdin.
* Return true if successful.
*/
static bool push_file(char *fname)
{
int fd = fname ? open(fname, O_RDONLY) : STDIN_FILENO;
has_infile = fname ? true : false;
if (fd < 0)
return false;
if (fd > fd_max)
fd_max = fd;
rio_ptr rnew = malloc_or_fail(sizeof(rio_t), "push_file");
rnew->fd = fd;
rnew->cnt = 0;
rnew->bufptr = rnew->buf;
rnew->prev = buf_stack;
buf_stack = rnew;
return true;
}
/* Pop a file buffer from stack */
static void pop_file()
{
if (buf_stack) {
rio_ptr rsave = buf_stack;
buf_stack = rsave->prev;
close(rsave->fd);
free_block(rsave, sizeof(rio_t));
}
}
/* Handling of input */
static void init_in()
{
buf_stack = NULL;
}
/* Read command from input file.
* When hit EOF, close that file and return NULL
*/
static char *readline()
{
int cnt;
char c;
char *lptr = linebuf;
if (!buf_stack)
return NULL;
for (cnt = 0; cnt < RIO_BUFSIZE - 2; cnt++) {
if (buf_stack->cnt <= 0) {
/* Need to read from input file */
buf_stack->cnt = read(buf_stack->fd, buf_stack->buf, RIO_BUFSIZE);
buf_stack->bufptr = buf_stack->buf;
if (buf_stack->cnt <= 0) {
/* Encountered EOF */
pop_file();
if (cnt > 0) {
/* Last line of file did not terminate with newline. */
/* Terminate line & return it */
*lptr++ = '\n';
*lptr++ = '\0';
if (echo) {
report_noreturn(1, prompt);
report_noreturn(1, linebuf);
}
return linebuf;
}
return NULL;
}
}
/* Have text in buffer */
c = *buf_stack->bufptr++;
*lptr++ = c;
buf_stack->cnt--;
if (c == '\n')
break;
}
if (c != '\n') {
/* Hit buffer limit. Artificially terminate line */
*lptr++ = '\n';
}
*lptr++ = '\0';
if (echo) {
report_noreturn(1, prompt);
report_noreturn(1, linebuf);
}
return linebuf;
}
static bool cmd_done()
{
return !buf_stack || quit_flag;
}
/*
* Handle command processing in program that uses select as main control loop.
* Like select, but checks whether command input either present in internal
* buffer
* or readable from command input. If so, that command is executed.
* Same return as select. Command input file removed from readfds
*
* nfds should be set to the maximum file descriptor for network sockets.
* If nfds == 0, this indicates that there is no pending network activity
*/
int cmd_select(int nfds,
fd_set *readfds,
fd_set *writefds,
fd_set *exceptfds,
struct timeval *timeout)
{
int infd;
fd_set local_readset;
if (cmd_done())
return 0;
if (!block_flag) {
/* Process any commands in input buffer */
if (!readfds)
readfds = &local_readset;
/* Add input fd to readset for select */
infd = buf_stack->fd;
FD_SET(infd, readfds);
if (infd == STDIN_FILENO && prompt_flag) {
printf("%s", prompt);
fflush(stdout);
prompt_flag = true;
}
if (infd >= nfds)
nfds = infd + 1;
}
if (nfds == 0)
return 0;
int result = select(nfds, readfds, writefds, exceptfds, timeout);
if (result <= 0)
return result;
infd = buf_stack->fd;
if (readfds && FD_ISSET(infd, readfds)) {
/* Commandline input available */
FD_CLR(infd, readfds);
result--;
if (has_infile) {
char *cmdline;
cmdline = readline();
if (cmdline)
interpret_cmd(cmdline);
}
}
return result;
}
bool finish_cmd()
{
bool ok = true;
if (!quit_flag)
ok = ok && do_quit_cmd(0, NULL);
has_infile = false;
return ok && err_cnt == 0;
}
static bool cmd_maybe(char *target, const char *src)
{
for (int i = 0; i < strlen(src); i++) {
if (target[i] == '\0')
return false;
if (src[i] != target[i])
return false;
}
return true;
}
void completion(const char *buf, linenoiseCompletions *lc)
{
if (strncmp("option ", buf, 7) == 0) {
param_ptr plist = param_list;
while (plist) {
char str[128] = "";
// if parameter is too long, now we just ignore it
if (strlen(plist->name) > 120)
continue;
strcat(str, "option ");
strcat(str, plist->name);
if (cmd_maybe(str, buf))
linenoiseAddCompletion(lc, str);
plist = plist->next;
}
return;
}
cmd_ptr clist = cmd_list;
while (clist) {
if (cmd_maybe(clist->name, buf))
linenoiseAddCompletion(lc, clist->name);
clist = clist->next;
}
}
bool run_console(char *infile_name)
{
if (!push_file(infile_name)) {
report(1, "ERROR: Could not open source file '%s'", infile_name);
return false;
}
if (!has_infile) {
char *cmdline;
while ((cmdline = linenoise(prompt)) != NULL) {
interpret_cmd(cmdline);
linenoiseHistoryAdd(cmdline); /* Add to the history. */
linenoiseHistorySave(HISTORY_FILE); /* Save the history on disk. */
linenoiseFree(cmdline);
}
} else {
while (!cmd_done())
cmd_select(0, NULL, NULL, NULL, NULL);
}
return err_cnt == 0;
}