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complement lab03

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yenru0
2025-11-24 03:03:35 +09:00
parent 3e87f2c37d
commit 1c50fbd315
1 changed files with 351 additions and 272 deletions
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623
labs/03_shlab/tsh.c
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@@ -4,21 +4,21 @@
* Name: <fill in> * Name: <fill in>
* Student id: <fill in> * Student id: <fill in>
*/ */
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <unistd.h>
#include <string.h> #include <string.h>
#include <ctype.h>
#include <signal.h>
#include <sys/types.h> #include <sys/types.h>
#include <sys/wait.h> #include <sys/wait.h>
#include <errno.h> #include <unistd.h>
/* Misc manifest constants */ /* Misc manifest constants */
#define MAXLINE 1024 /* max line size */ #define MAXLINE 1024 /* max line size */
#define MAXARGS 128 /* max args on a command line */ #define MAXARGS 128 /* max args on a command line */
#define MAXJOBS 16 /* max jobs at any point in time */ #define MAXJOBS 16 /* max jobs at any point in time */
#define MAXJID 1<<16 /* max job ID */ #define MAXJID 1 << 16 /* max job ID */
/* Job states */ /* Job states */
#define UNDEF 0 /* undefined */ #define UNDEF 0 /* undefined */
@@ -37,22 +37,21 @@
*/ */
/* Global variables */ /* Global variables */
extern char **environ; /* defined in libc */ extern char **environ; /* defined in libc */
char prompt[] = "tsh> "; /* command line prompt (DO NOT CHANGE) */ char prompt[] = "tsh> "; /* command line prompt (DO NOT CHANGE) */
int verbose = 0; /* if true, print additional output */ int verbose = 0; /* if true, print additional output */
int nextjid = 1; /* next job ID to allocate */ int nextjid = 1; /* next job ID to allocate */
char sbuf[MAXLINE]; /* for composing sprintf messages */ char sbuf[MAXLINE]; /* for composing sprintf messages */
struct job_t { /* The job struct */ struct job_t { /* The job struct */
pid_t pid; /* job PID */ pid_t pid; /* job PID */
int jid; /* job ID [1, 2, ...] */ int jid; /* job ID [1, 2, ...] */
int state; /* UNDEF, BG, FG, or ST */ int state; /* UNDEF, BG, FG, or ST */
char cmdline[MAXLINE]; /* command line */ char cmdline[MAXLINE]; /* command line */
}; };
struct job_t jobs[MAXJOBS]; /* The job list */ struct job_t jobs[MAXJOBS]; /* The job list */
/* End global variables */ /* End global variables */
/* Function prototypes */ /* Function prototypes */
/*---------------------------------------------------------------------------- /*----------------------------------------------------------------------------
@@ -94,68 +93,67 @@ handler_t *Signal(int signum, handler_t *handler);
/* /*
* main - The shell's main routine * main - The shell's main routine
*/ */
int main(int argc, char **argv) int main(int argc, char **argv) {
{ char c;
char c; char cmdline[MAXLINE];
char cmdline[MAXLINE]; int emit_prompt = 1; /* emit prompt (default) */
int emit_prompt = 1; /* emit prompt (default) */
/* Redirect stderr to stdout (so that driver will get all output /* Redirect stderr to stdout (so that driver will get all output
* on the pipe connected to stdout) */ * on the pipe connected to stdout) */
dup2(1, 2); dup2(1, 2);
/* Parse the command line */ /* Parse the command line */
while ((c = getopt(argc, argv, "hvp")) != EOF) { while ((c = getopt(argc, argv, "hvp")) != EOF) {
switch (c) { switch (c) {
case 'h': /* print help message */ case 'h': /* print help message */
usage(); usage();
break; break;
case 'v': /* emit additional diagnostic info */ case 'v': /* emit additional diagnostic info */
verbose = 1; verbose = 1;
break; break;
case 'p': /* don't print a prompt */ case 'p': /* don't print a prompt */
emit_prompt = 0; /* handy for automatic testing */ emit_prompt = 0; /* handy for automatic testing */
break; break;
default: default:
usage(); usage();
} }
} }
/* Install the signal handlers */ /* Install the signal handlers */
/* These are the ones you will need to implement */ /* These are the ones you will need to implement */
Signal(SIGINT, sigint_handler); /* ctrl-c */ Signal(SIGINT, sigint_handler); /* ctrl-c */
Signal(SIGTSTP, sigtstp_handler); /* ctrl-z */ Signal(SIGTSTP, sigtstp_handler); /* ctrl-z */
Signal(SIGCHLD, sigchld_handler); /* Terminated or stopped child */ Signal(SIGCHLD, sigchld_handler); /* Terminated or stopped child */
/* This one provides a clean way to kill the shell */ /* This one provides a clean way to kill the shell */
Signal(SIGQUIT, sigquit_handler); Signal(SIGQUIT, sigquit_handler);
/* Initialize the job list */ /* Initialize the job list */
initjobs(jobs); initjobs(jobs);
/* Execute the shell's read/eval loop */ /* Execute the shell's read/eval loop */
while (1) { while (1) {
/* Read command line */ /* Read command line */
if (emit_prompt) { if (emit_prompt) {
printf("%s", prompt); printf("%s", prompt);
fflush(stdout); fflush(stdout);
} }
if ((fgets(cmdline, MAXLINE, stdin) == NULL) && ferror(stdin)) if ((fgets(cmdline, MAXLINE, stdin) == NULL) && ferror(stdin))
app_error("fgets error"); app_error("fgets error");
if (feof(stdin)) { /* End of file (ctrl-d) */ if (feof(stdin)) { /* End of file (ctrl-d) */
fflush(stdout); fflush(stdout);
exit(0); exit(0);
} }
/* Evaluate the command line */ /* Evaluate the command line */
eval(cmdline); eval(cmdline);
fflush(stdout); fflush(stdout);
fflush(stdout); fflush(stdout);
} }
exit(0); /* control never reaches here */ exit(0); /* control never reaches here */
} }
/* /*
@@ -169,9 +167,30 @@ int main(int argc, char **argv)
* background children don't receive SIGINT (SIGTSTP) from the kernel * background children don't receive SIGINT (SIGTSTP) from the kernel
* when we type ctrl-c (ctrl-z) at the keyboard. * when we type ctrl-c (ctrl-z) at the keyboard.
*/ */
void eval(char *cmdline) void eval(char *cmdline) {
{ pid_t pid;
return; char *argv[MAXARGS];
int bg = parseline(cmdline, argv);
if (argv[0] && !builtin_cmd(argv)) {
if ((pid = fork()) == 0) {// Child process
setpgid(0, 0); // Set new process group
if (execve(argv[0], argv, environ) < 0) {
printf("%s: Command not found\n", argv[0]);
exit(0);
}
}
if (!bg) {// Foreground job
addjob(jobs, pid, FG, cmdline);
waitfg(pid);
} else {// Background job
addjob(jobs, pid, BG, cmdline);
fprintf(stderr, "[%d] (%d) %s", pid2jid(pid), pid, cmdline);
}
}
} }
/* /*
@@ -181,79 +200,133 @@ void eval(char *cmdline)
* argument. Return true if the user has requested a BG job, false if * argument. Return true if the user has requested a BG job, false if
* the user has requested a FG job. * the user has requested a FG job.
*/ */
int parseline(const char *cmdline, char **argv) int parseline(const char *cmdline, char **argv) {
{ static char array[MAXLINE]; /* holds local copy of command line */
static char array[MAXLINE]; /* holds local copy of command line */ char *buf = array; /* ptr that traverses command line */
char *buf = array; /* ptr that traverses command line */ char *delim; /* points to first space delimiter */
char *delim; /* points to first space delimiter */ int argc; /* number of args */
int argc; /* number of args */ int bg; /* background job? */
int bg; /* background job? */
strcpy(buf, cmdline); strcpy(buf, cmdline);
buf[strlen(buf)-1] = ' '; /* replace trailing '\n' with space */ buf[strlen(buf) - 1] = ' '; /* replace trailing '\n' with space */
while (*buf && (*buf == ' ')) /* ignore leading spaces */ while (*buf && (*buf == ' ')) /* ignore leading spaces */
buf++; buf++;
/* Build the argv list */ /* Build the argv list */
argc = 0; argc = 0;
if (*buf == '\'') { if (*buf == '\'') {
buf++; buf++;
delim = strchr(buf, '\''); delim = strchr(buf, '\'');
} } else {
else { delim = strchr(buf, ' ');
delim = strchr(buf, ' '); }
}
while (delim) { while (delim) {
argv[argc++] = buf; argv[argc++] = buf;
*delim = '\0'; *delim = '\0';
buf = delim + 1; buf = delim + 1;
while (*buf && (*buf == ' ')) /* ignore spaces */ while (*buf && (*buf == ' ')) /* ignore spaces */
buf++; buf++;
if (*buf == '\'') { if (*buf == '\'') {
buf++; buf++;
delim = strchr(buf, '\''); delim = strchr(buf, '\'');
} } else {
else { delim = strchr(buf, ' ');
delim = strchr(buf, ' '); }
} }
} argv[argc] = NULL;
argv[argc] = NULL;
if (argc == 0) /* ignore blank line */ if (argc == 0) /* ignore blank line */
return 1; return 1;
/* should the job run in the background? */ /* should the job run in the background? */
if ((bg = (*argv[argc-1] == '&')) != 0) { if ((bg = (*argv[argc - 1] == '&')) != 0) {
argv[--argc] = NULL; argv[--argc] = NULL;
} }
return bg; return bg;
} }
/* /*
* builtin_cmd - If the user has typed a built-in command then execute * builtin_cmd - If the user has typed a built-in command then execute
* it immediately. * it immediately.
*/ */
int builtin_cmd(char **argv) int builtin_cmd(char **argv) {
{ // Built-in-commands: jobs, bg, fg, quit
return 0; /* not a builtin command */
if (!strcmp(argv[0], "quit")) {
exit(0);
} else if (!strcmp(argv[0], "jobs")) {
listjobs(jobs);
return 1;
} else if (!strcmp(argv[0], "bg") || !strcmp(argv[0], "fg")) {
do_bgfg(argv);
return 1;
}
return 0;
} }
/* /*
* do_bgfg - Execute the builtin bg and fg commands * do_bgfg - Execute the builtin bg and fg commands
*/ */
void do_bgfg(char **argv) void do_bgfg(char **argv) {
{ struct job_t *job = NULL;
return; pid_t pid;
int jid;
if (argv[1] == NULL) {
printf("%s command requires PID or %%jobid argument\n", argv[0]);
return;
}
if (argv[1][0] == '%') {
if (sscanf(&argv[1][1], "%d", &jid) != 1) {
printf("%s: argument must be a PID or %%jobid\n", argv[0]);
return;
}
job = getjobjid(jobs, jid);
if (job == NULL) {
printf("%s: No such job\n", argv[1]);
return;
}
} else if (isdigit((unsigned char) argv[1][0])) {
if (sscanf(argv[1], "%d", &pid) != 1) {
printf("%s: argument must be a PID or %%jobid\n", argv[0]);
return;
}
job = getjobpid(jobs, pid);
if (job == NULL) {
printf("(%s): No such process\n", argv[1]);
return;
}
} else {
printf("%s: argument must be a PID or %%jobid\n", argv[0]);
return;
}
pid = job->pid;
if (!strcmp(argv[0], "bg")) {
job->state = BG;
if (kill(-pid, SIGCONT) < 0)
unix_error("kill (SIGCONT) error");
printf("[%d] (%d) %s", job->jid, job->pid, job->cmdline);
} else { /* fg */
job->state = FG;
if (kill(-pid, SIGCONT) < 0)
unix_error("kill (SIGCONT) error");
waitfg(pid);
}
} }
/* /*
* waitfg - Block until process pid is no longer the foreground process * waitfg - Block until process pid is no longer the foreground process
*/ */
void waitfg(pid_t pid) void waitfg(pid_t pid) {
{ while (pid == fgpid(jobs)) {
return; sleep(1);
}
return;
} }
/***************** /*****************
@@ -267,9 +340,27 @@ void waitfg(pid_t pid)
* available zombie children, but doesn't wait for any other * available zombie children, but doesn't wait for any other
* currently running children to terminate. * currently running children to terminate.
*/ */
void sigchld_handler(int sig) void sigchld_handler(int sig) {
{ int olderrno = errno;
return; pid_t pid;
int status;
while ((pid = waitpid(-1, &status, WNOHANG | WUNTRACED)) > 0) {
if (WIFEXITED(status)) {
deletejob(jobs, pid);
} else if (WIFSIGNALED(status)) {
fprintf(stderr, "Job [%d] (%d) terminated by signal %d\n", pid2jid(pid), pid, WTERMSIG(status));
deletejob(jobs, pid);
} else if (WIFSTOPPED(status)) {
struct job_t *job = getjobpid(jobs, pid);
if (job != NULL) {
job->state = ST;
fprintf(stderr, "Job [%d] (%d) stopped by signal %d\n", job->jid, pid, WSTOPSIG(status));
}
}
}
errno = olderrno;
} }
/* /*
@@ -277,9 +368,11 @@ void sigchld_handler(int sig)
* user types ctrl-c at the keyboard. Catch it and send it along * user types ctrl-c at the keyboard. Catch it and send it along
* to the foreground job. * to the foreground job.
*/ */
void sigint_handler(int sig) void sigint_handler(int sig) {
{ pid_t pid;
return; if ((pid = fgpid(jobs)) > 0) {
kill(-pid, SIGINT);
}
} }
/* /*
@@ -287,9 +380,11 @@ void sigint_handler(int sig)
* the user types ctrl-z at the keyboard. Catch it and suspend the * the user types ctrl-z at the keyboard. Catch it and suspend the
* foreground job by sending it a SIGTSTP. * foreground job by sending it a SIGTSTP.
*/ */
void sigtstp_handler(int sig) void sigtstp_handler(int sig) {
{ pid_t pid;
return; if ((pid = fgpid(jobs)) > 0) {
kill(-pid, SIGTSTP);
}
} }
/********************* /*********************
@@ -301,160 +396,149 @@ void sigtstp_handler(int sig)
**********************************************/ **********************************************/
/* clearjob - Clear the entries in a job struct */ /* clearjob - Clear the entries in a job struct */
void clearjob(struct job_t *job) void clearjob(struct job_t *job) {
{ job->pid = 0;
job->pid = 0; job->jid = 0;
job->jid = 0; job->state = UNDEF;
job->state = UNDEF; job->cmdline[0] = '\0';
job->cmdline[0] = '\0';
} }
/* initjobs - Initialize the job list */ /* initjobs - Initialize the job list */
void initjobs(struct job_t *jobs) void initjobs(struct job_t *jobs) {
{ int i;
int i;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
clearjob(&jobs[i]); clearjob(&jobs[i]);
} }
/* maxjid - Returns largest allocated job ID */ /* maxjid - Returns largest allocated job ID */
int maxjid(struct job_t *jobs) int maxjid(struct job_t *jobs) {
{ int i, max = 0;
int i, max=0;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
if (jobs[i].jid > max) if (jobs[i].jid > max)
max = jobs[i].jid; max = jobs[i].jid;
return max; return max;
} }
/* addjob - Add a job to the job list */ /* addjob - Add a job to the job list */
int addjob(struct job_t *jobs, pid_t pid, int state, char *cmdline) int addjob(struct job_t *jobs, pid_t pid, int state, char *cmdline) {
{ int i;
int i;
if (pid < 1) if (pid < 1)
return 0; return 0;
for (i = 0; i < MAXJOBS; i++) { for (i = 0; i < MAXJOBS; i++) {
if (jobs[i].pid == 0) { if (jobs[i].pid == 0) {
jobs[i].pid = pid; jobs[i].pid = pid;
jobs[i].state = state; jobs[i].state = state;
jobs[i].jid = nextjid++; jobs[i].jid = nextjid++;
if (nextjid > MAXJOBS) if (nextjid > MAXJOBS)
nextjid = 1; nextjid = 1;
strcpy(jobs[i].cmdline, cmdline); strcpy(jobs[i].cmdline, cmdline);
if(verbose){ if (verbose) {
printf("Added job [%d] %d %s\n", jobs[i].jid, jobs[i].pid, jobs[i].cmdline); printf("Added job [%d] %d %s\n", jobs[i].jid, jobs[i].pid, jobs[i].cmdline);
} }
return 1; return 1;
} }
} }
printf("Tried to create too many jobs\n"); printf("Tried to create too many jobs\n");
return 0; return 0;
} }
/* deletejob - Delete a job whose PID=pid from the job list */ /* deletejob - Delete a job whose PID=pid from the job list */
int deletejob(struct job_t *jobs, pid_t pid) int deletejob(struct job_t *jobs, pid_t pid) {
{ int i;
int i;
if (pid < 1) if (pid < 1)
return 0; return 0;
for (i = 0; i < MAXJOBS; i++) { for (i = 0; i < MAXJOBS; i++) {
if (jobs[i].pid == pid) { if (jobs[i].pid == pid) {
clearjob(&jobs[i]); clearjob(&jobs[i]);
nextjid = maxjid(jobs)+1; nextjid = maxjid(jobs) + 1;
return 1; return 1;
} }
} }
return 0; return 0;
} }
/* fgpid - Return PID of current foreground job, 0 if no such job */ /* fgpid - Return PID of current foreground job, 0 if no such job */
pid_t fgpid(struct job_t *jobs) pid_t fgpid(struct job_t *jobs) {
{ int i;
int i;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
if (jobs[i].state == FG) if (jobs[i].state == FG)
return jobs[i].pid; return jobs[i].pid;
return 0; return 0;
} }
/* getjobpid - Find a job (by PID) on the job list */ /* getjobpid - Find a job (by PID) on the job list */
struct job_t *getjobpid(struct job_t *jobs, pid_t pid) struct job_t *getjobpid(struct job_t *jobs, pid_t pid) {
{ int i;
int i;
if (pid < 1) if (pid < 1)
return NULL; return NULL;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
if (jobs[i].pid == pid) if (jobs[i].pid == pid)
return &jobs[i]; return &jobs[i];
return NULL; return NULL;
} }
/* getjobjid - Find a job (by JID) on the job list */ /* getjobjid - Find a job (by JID) on the job list */
struct job_t *getjobjid(struct job_t *jobs, int jid) struct job_t *getjobjid(struct job_t *jobs, int jid) {
{ int i;
int i;
if (jid < 1) if (jid < 1)
return NULL; return NULL;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
if (jobs[i].jid == jid) if (jobs[i].jid == jid)
return &jobs[i]; return &jobs[i];
return NULL; return NULL;
} }
/* pid2jid - Map process ID to job ID */ /* pid2jid - Map process ID to job ID */
int pid2jid(pid_t pid) int pid2jid(pid_t pid) {
{ int i;
int i;
if (pid < 1) if (pid < 1)
return 0; return 0;
for (i = 0; i < MAXJOBS; i++) for (i = 0; i < MAXJOBS; i++)
if (jobs[i].pid == pid) { if (jobs[i].pid == pid) {
return jobs[i].jid; return jobs[i].jid;
} }
return 0; return 0;
} }
/* listjobs - Print the job list */ /* listjobs - Print the job list */
void listjobs(struct job_t *jobs) void listjobs(struct job_t *jobs) {
{ int i;
int i;
for (i = 0; i < MAXJOBS; i++) { for (i = 0; i < MAXJOBS; i++) {
if (jobs[i].pid != 0) { if (jobs[i].pid != 0) {
printf("[%d] (%d) ", jobs[i].jid, jobs[i].pid); printf("[%d] (%d) ", jobs[i].jid, jobs[i].pid);
switch (jobs[i].state) { switch (jobs[i].state) {
case BG: case BG:
printf("Running "); printf("Running ");
break; break;
case FG: case FG:
printf("Foreground "); printf("Foreground ");
break; break;
case ST: case ST:
printf("Stopped "); printf("Stopped ");
break; break;
default: default:
printf("listjobs: Internal error: job[%d].state=%d ", printf("listjobs: Internal error: job[%d].state=%d ",
i, jobs[i].state); i, jobs[i].state);
} }
printf("%s", jobs[i].cmdline); printf("%s", jobs[i].cmdline);
} }
} }
} }
/****************************** /******************************
* end job list helper routines * end job list helper routines
******************************/ ******************************/
/*********************** /***********************
* Other helper routines * Other helper routines
***********************/ ***********************/
@@ -462,55 +546,50 @@ void listjobs(struct job_t *jobs)
/* /*
* usage - print a help message * usage - print a help message
*/ */
void usage(void) void usage(void) {
{ printf("Usage: shell [-hvp]\n");
printf("Usage: shell [-hvp]\n"); printf(" -h print this message\n");
printf(" -h print this message\n"); printf(" -v print additional diagnostic information\n");
printf(" -v print additional diagnostic information\n"); printf(" -p do not emit a command prompt\n");
printf(" -p do not emit a command prompt\n"); exit(1);
exit(1);
} }
/* /*
* unix_error - unix-style error routine * unix_error - unix-style error routine
*/ */
void unix_error(char *msg) void unix_error(char *msg) {
{ fprintf(stdout, "%s: %s\n", msg, strerror(errno));
fprintf(stdout, "%s: %s\n", msg, strerror(errno)); exit(1);
exit(1);
} }
/* /*
* app_error - application-style error routine * app_error - application-style error routine
*/ */
void app_error(char *msg) void app_error(char *msg) {
{ fprintf(stdout, "%s\n", msg);
fprintf(stdout, "%s\n", msg); exit(1);
exit(1);
} }
/* /*
* Signal - wrapper for the sigaction function * Signal - wrapper for the sigaction function
*/ */
handler_t *Signal(int signum, handler_t *handler) handler_t *Signal(int signum, handler_t *handler) {
{ struct sigaction action, old_action;
struct sigaction action, old_action;
action.sa_handler = handler; action.sa_handler = handler;
sigemptyset(&action.sa_mask); /* block sigs of type being handled */ sigemptyset(&action.sa_mask); /* block sigs of type being handled */
action.sa_flags = SA_RESTART; /* restart syscalls if possible */ action.sa_flags = SA_RESTART; /* restart syscalls if possible */
if (sigaction(signum, &action, &old_action) < 0) if (sigaction(signum, &action, &old_action) < 0)
unix_error("Signal error"); unix_error("Signal error");
return (old_action.sa_handler); return (old_action.sa_handler);
} }
/* /*
* sigquit_handler - The driver program can gracefully terminate the * sigquit_handler - The driver program can gracefully terminate the
* child shell by sending it a SIGQUIT signal. * child shell by sending it a SIGQUIT signal.
*/ */
void sigquit_handler(int sig) void sigquit_handler(int sig) {
{ printf("Terminating after receipt of SIGQUIT signal\n");
printf("Terminating after receipt of SIGQUIT signal\n"); exit(1);
exit(1);
} }