Added ps basic functionality

1 files changed, 307 insertions, 281 deletions

diff --git a/src/ps.c b/src/ps.c
index bc090ec..3892271 100644
--- a/src/ps.c
+++ b/src/ps.c
@@ -12,272 +12,354 @@
 #include <limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <grp.h>
+#include <grp.h>
+#include <pwd.h>
+
+/*
+** TODO
+** time formatting
+** bug with random pid without optimization
+** command line args
+** process selection
+*/
 
 #define PROC_DIR "/proc"
 
-#define TASK_COMM_LEN 32
-
-static int page_size   = -1;
-static long clock_tick = -1;
 
-typedef enum
-{
-	FIELD_ARGS,
-	FIELD_COMM,
-	FIELD_PID,
-	FIELD_PPID,
-	FIELD_PGID,
-	FIELD_ETIME,
-	FIELD_TIME,
-	FIELD_GROUP,
-	FIELD_RGROUP,
-	FIELD_USER,
-	FIELD_RUSER,
-	FIELD_NICE,
-	FIELD_TTY,
-	FIELD_PCPU,
-	FIELD_VSZ,
-	FIELD_ADDR,
-	FIELD_ADDR,
-	FIELD_C,
-	FIELD_PRI,
-	FIELD_NI,
-	FIELD_ADDR,
-	FIELD_SZ,
-	FIELD_WCHAN,
-} t_field_id;
-
-typedef struct
+struct s_field_info
 {
-	t_field_id id;
 	char       *specifier;
 	char       *header;
 	int        width;
-} t_field_info;
-
-static t_field_info field_infos[] = {
-	{FIELD_ARGS,   "args",   "COMMAND", 30},
-	{FIELD_COMM,   "comm",   "COMMAND", -1},
-	{FIELD_PID,    "pid",    "PID",     8},
-	{FIELD_PPID,   "ppid",   "PPID",    8},
-	{FIELD_PGID,   "pgid",   "PGID",    8},
-	{FIELD_ETIME,  "etime",  "ELAPSED", -1},
-	{FIELD_TIME,   "time",   "TIME",    -1},
-	{FIELD_GROUP,  "group",  "GROUP",   -1},
-	{FIELD_RGROUP, "rgroup", "RGROUP",  -1},
-	{FIELD_USER,   "user",   "USER",    -1},
-	{FIELD_RUSER,  "ruser",  "RUSER",   -1},
-	{FIELD_NICE,   "nice",   "NI",      -1},
-	{FIELD_TTY,    "tty",    "TT",      -1},
-	{FIELD_PCPU,   "pcpu",   "%CPU",    -1},
-	{FIELD_VSZ,    "vsz",    "VSZ",     -1},
-	{FIELD_FLAGS,  "f",      "F",       1},
-	{FIELD_STATE,  "s",      "S",       1},
-	{FIELD_C,      "c",      "C",       -1},
-	{FIELD_PRI,    "pri",    "PRI",     -1},
-	{FIELD_ADDR,   "addr",   "ADDR",    -1},
-	{FIELD_SZ,     "sz",     "SZ",      -1},
-	{FIELD_WCHAN,  "wchan",  "WCHAN",   -1},
+	void       (*print_func)(struct s_field_info *info);
 };
+typedef struct s_field_info t_field_info;
 
+// globals
+#define TASK_COMM_LEN 32
 
-t_field_info *filed_info_from_specifier(const char *specifier)
-{
-	for (size_t i = 0; i < sizeof(field_infos) / sizeof(t_field_info); i++)
-		if (strcmp(field_infos[i].specifier, specifier) == 0)
-			return (&field_infos[i]);
-	return (NULL);
-}
+static int  g_page_size  = -1;
+static long g_clock_tick = -1;
+
+static char g_file_path[PATH_MAX + 1];
+
+static char g_comm[TASK_COMM_LEN];
 
-static struct stat proc_statbuf;
-static char        *stat_file;
-static char        *cmdfile_file;
+static pid_t g_pid;
+static pid_t g_ppid;
+static pid_t g_pgrp;
 
-void print_field_resource(t_field_info *field_info)
+static uid_t g_uid;
+static gid_t g_gid;
+
+static long g_nice;
+static long g_priority;
+
+static unsigned long long g_starttime;
+
+static int g_tty_nr;
+
+static unsigned long g_vsize;
+static unsigned long g_rss;
+static unsigned      g_flags;
+static char          g_state;
+static char          g_state;
+static unsigned long g_wchan;
+
+void print_func_args(t_field_info *info)
 {
-	switch (field_info->id)
+	snprintf(g_file_path, PATH_MAX, PROC_DIR"/%d/cmdline", g_pid);
+	FILE *cmdline_file = fopen(g_file_path, "r");
+	if (cmdline_file == NULL)
+		return;
+	int count = 0;
+	int c = EOF;
+	while ((c = fgetc(cmdline_file)) != EOF)
 	{
-		case FIELD_ARGS:
-			snprintf(file_path, PATH_MAX, "%s/%d/cmdline", PROC_DIR, pid);
-			FILE *cmdline_file = fopen(file_path, "r");
-			if (cmdline_file == NULL)
-				return;
-			int c = EOF;
-			while ((c = fgetc(cmdline_file)) != EOF)
-				fputc(c, stdout);
+		fputc(c, stdout);
+		count++;
+		if (count > info->width)
 			break;
+	}
+	while (count < info->width)
+		fputc(' ', stdout);
+}
 
-		case FIELD_COMM:
-			char *closing_parent = strrchr(proc_stat.comm + 0, ')');
-			if (closing_parent != NULL)
-				*closing_parent = '\0';
-			printf("%s", proc_stat.comm + 1);
-			break;
+void print_func_comm(t_field_info *info)
+{
+	char *closing_parent = strrchr(g_comm, ')');
+	if (closing_parent != NULL)
+		*closing_parent = '\0';
+	printf(
+		"%*s",
+		info->width,
+		g_comm[0] == '(' ? (g_comm + 1) : g_comm
+	);
+}
 
-		case FIELD_PID:  printf("%*ld ", info.width, proc_stat.pid);  break;
-		case FIELD_PPID: printf("%*ld ", info.width, proc_stat.ppid); break;
-		case FIELD_PGID: printf("%*ld ", info.width, proc_stat.pgrp); break;
+void print_func_pid(t_field_info *info)  { printf("%*d", info->width, g_pid);  }  // bug without -O flag
+void print_func_ppid(t_field_info *info) { printf("%*d", info->width, g_ppid); }
+void print_func_pgrp(t_field_info *info) { printf("%*d", info->width, g_pgrp); }
 
-		case FIELD_ETIME:
-			printf("%6lld ", /*current -*/ proc_stat.starttime / clock_tick);
-			break;
-		case FIELD_TIME:
-			printf("%6lld ", proc_stat.starttime / clock_tick);
-			break;
+void print_func_etime(t_field_info *info)
+{
+	printf("%*lld ", info->width, /*current -*/ g_starttime / g_clock_tick);
+}
 
-		case FIELD_GROUP:
-			break;
-		case FIELD_RGROUP:
-			break;
-		case FIELD_USER:
-			printf("%6d ", proc_statbuf.st_uid);
-			break;
-		case FIELD_RUSER:
-			break;
+void print_func_time(t_field_info *info)
+{
+	printf("%*lld ", info->width, g_starttime / g_clock_tick);
+}
 
-		case FIELD_NICE:
-			printf("%3ld ", proc_stat.nice);
-			break;
-		case FIELD_PRI:
-			printf("%3ld ", proc_stat.priority);
-			break;
+void print_func_user(t_field_info *info)
+{
+	struct passwd *passwd_ptr = getpwuid(g_uid);
+	if (passwd_ptr == NULL)
+		return;
+	printf("%*.*s", info->width, info->width, passwd_ptr->pw_name);
+}
 
-		case FIELD_TTY:
-			printf("%6d ", proc_stat.tty_nr);
-			break;
-		case FIELD_PCPU:
-			break;
-		case FIELD_VSZ:
-			printf("%5ld ", proc_stat.vsize / page_size);
-			break;
-		case FIELD_ADDR:
-			break;
-		case FIELD_FLAGS:
-			printf("%o ", 0); //proc_stat.flags,
-			break;
-		case FIELD_STATE:
-			printf("%c ", proc_stat.state);
-			break;
+void print_func_group(t_field_info *info)
+{
+	struct group *group_ptr = getgrgid(g_gid);
+	if (group_ptr == NULL)
+		return;
+	printf("%*.*s", info->width, info->width, group_ptr->gr_name);
+}
 
-		case FIELD_C:
-			break;
-		case FIELD_SZ:
-			break;
+void print_func_nice(t_field_info *info)     { printf("%*ld", info->width, g_nice);     }
+void print_func_priority(t_field_info *info) { printf("%*ld", info->width, g_priority); }
 
-		case FIELD_WCHAN:
-			printf("%4ld ", proc_stat.wchan);
-			break;
 
-		default:
-			exit(1);
+bool find_tty_in_dir(char *dir_path, char dest[PATH_MAX + 1])
+{
+	DIR *dir = opendir(dir_path);
+	if (dir == NULL)
+		return false;
+	struct dirent *entry;
+	strcpy(dest, dir_path);
+	strcat(dest, "/");
+	char *dest_end = dest + strlen(dest);
+	while ((entry = readdir(dir)) != NULL)
+	{
+		strcat(dest, entry->d_name);
+		struct stat statbuf;
+		if (lstat(dest, &statbuf) == -1)
+			return false;
+		if ((statbuf.st_mode & S_IFMT) == S_IFCHR &&
+			 statbuf.st_rdev == (dev_t)g_tty_nr)
+			return true;
+		*dest_end = '\0';
+	}
+	return false;
+}
+
+void print_func_tty(t_field_info *info)
+{
+	if (g_tty_nr == 0)
+	{
+		printf("%*c", info->width, '?');
+		return;
+	}
+
+	char tty_path[PATH_MAX + 1] = {0};
+	bool res = find_tty_in_dir("/dev", tty_path) ||
+		       find_tty_in_dir("/dev/pts", tty_path);
+	if (!res)
+	{
+		printf("%*c", info->width, '?');
+		return;
 	}
+	printf("%*s", info->width, tty_path + 5);
 }
 
-char full_format[]    = "user pid ppid c stime tty time args";
-char long_format[]    = "f s user pid ppid c pri ni addr sz wchan tty time cmd";
-char default_format[] = "pid tty time cmd";
 
-size_t         fields_size = 0;
-t_field_info **field_infos = NULL;
+// sum of 1 if didn't exec and 4 if used super-user privileges
+void print_func_flags(t_field_info *info) { printf("%*o",  info->width, 0); }
+void print_func_state(t_field_info *info) { printf("%*c",   info->width, g_state); }
+void print_func_wchan(t_field_info *info) { printf("%*lu",  info->width, g_wchan); }
+void print_func_sz(t_field_info *info)   { printf("%*lu", info->width, g_vsize / g_page_size); }
+void print_func_vsz(t_field_info *info)    { printf("%*lu", info->width, g_rss); }
+
+void print_func_cpu(t_field_info *info) { printf("%*u", info->width, 2); }
+void print_func_addr(t_field_info *info) { printf("%*c", info->width, '-'); }
 
-void field_infos_from_format(char *format)
+static t_field_info field_infos[] =
 {
-	size_t i;
+	{"args",   "COMMAND", -30, &print_func_args},
+	{"comm",   "COMMAND", -30, &print_func_comm},
+	{"pid",    "PID",     7, &print_func_pid},
+	{"ppid",   "PPID",    7, &print_func_ppid},
+	{"pgid",   "PGID",    7, &print_func_pgrp},
+	{"etime",  "ELAPSED", 10, &print_func_etime},
+	{"time",   "TIME",    10, &print_func_time},
+
+	{"group",  "GROUP",   -8, &print_func_group},
+	{"rgroup", "RGROUP",  -8, &print_func_group},
+	{"user",   "USER",    -8, &print_func_user},
+	{"ruser",  "RUSER",   -8, &print_func_user},  // real user in /proc/[pid]/status file
+
+	{"nice",   "NI",       3, &print_func_nice},
+	{"pri",    "PRI",      3, &print_func_priority},
+	{"tty",    "TTY",      -6, &print_func_tty},
+	{"f",      "F",        1, &print_func_flags},
+	{"s",      "S",        1, &print_func_state},
+	{"vsz",    "VSZ",      9, &print_func_vsz},
+	{"sz",     "SZ",       9, &print_func_sz},
+	{"wchan",  "WCHAN",    -6, &print_func_wchan},
+
+	{"c",      "C",        2, &print_func_cpu},
+	{"addr",   "ADDR",     4, &print_func_addr},
+};
+
+
+t_field_info *field_info_from_specifier(const char *specifier)
+{
+	for (size_t i = 0; i < sizeof(field_infos) / sizeof(t_field_info); i++)
+		if (strcmp(field_infos[i].specifier, specifier) == 0)
+			return (&field_infos[i]);
+	return (NULL);
+}
+
+static char g_full_format[]    = "user pid ppid c stime tty time args";
+static char g_long_format[]    = "f s user pid ppid c pri nice addr sz wchan tty time comm";
+static char g_default_format[] = "pid tty time comm";
+
+#define MINOR_MASK 0b01111111111100000000000000000000
+#define MINOR_MASK 0b01111111111100000000000000000000
 
+static size_t         g_fields_size = 0;
+static t_field_info **g_fields = NULL;
+
+void fields_from_format(char *format)
+{
+	size_t i;
 	for (i = 0; format[i] != '\0'; i++)
 		if (isspace(format[i]) && isspace(format[i + 1]))
 			exit(1);
-
-	fields_size = 0;
+	g_fields_size = 1;
 	for (i = 0; format[i] != '\0'; i++)
 		if (isspace(format[i]))
-			fields_size++;
-
-	field_infos = malloc(fields_size * sizeof(t_field_info*));
-	if (field_infos == NULL)
+			g_fields_size++;
+	g_fields = malloc(g_fields_size * sizeof(t_field_info*));
+	if (g_fields == NULL)
 		exit(1);
-
 	i = 0;
 	char *specifier = NULL;
 	while ((specifier = strsep(&format, " ,")) != NULL)
 	{
-		field_infos[i] = field_info_from_specifier(specifier);
-		if (field_infos[i] == NULL)
+		g_fields[i] = field_info_from_specifier(specifier);
+		if (g_fields[i] == NULL)
+		{
+			fprintf(stderr, "Error: %s: is not a valid specifier\n", specifier);
 			exit(1);
+		}
 		i++;
 	}
 }
 
-void print_header(void)
+void print_fields_headers(void)
 {
-	for (size_t i = 0; i < fields_size; i++)
-		printf("%*s ", field_infos[i].width, field_infos[i].header);
+	for (size_t i = 0; i < g_fields_size; i++)
+		printf("%*s ", g_fields[i]->width, g_fields[i]->header);
+	fputc('\n', stdout);
 }
 
-typedef struct
+/*
+static
+struct
 {
-	pid_t              pid;
-	char               comm[TASK_COMM_LEN];
-	char               state;
-	pid_t              ppid;
-	pid_t              pgrp;
-	int                session;
-	int                tty_nr;
-	int                tpgid;
-	unsigned int       flags;
-	unsigned long      minflt;
-	unsigned long      cminflt;
-	unsigned long      majflt;
-	unsigned long      cmajflt;
-	unsigned long      utime;
-	unsigned long      stime;
-	long               cutime;
-	long               cstime;
-	long               priority;
-	long               nice;
-	long               num_threads;
-	long               itrealvalue;
-	unsigned long long starttime;
-	unsigned long      vsize;
-	long               rss;
-	unsigned long      rsslim;
-	unsigned long      startcode;
-	unsigned long      endcode;
-	unsigned long      startstack;
-	unsigned long      kstkesp;
-	unsigned long      kstkeip;
-	unsigned long      signal;
-	unsigned long      blocked;
-	unsigned long      sigignore;
-	unsigned long      sigcatch;
-	unsigned long      wchan;
-	unsigned long      nswap;
-	unsigned long      cnswap;
-	int                exit_signal;
-	int                processor;
-	unsigned int       rt_priority;
-	unsigned long      delayacct_blkio_ticks;
-	unsigned long      guest_time;
-	long               cguest_time;
-	unsigned long      end_data;
-	unsigned long      start_brk;
-	unsigned long      arg_start;
-	unsigned long      arg_end;
-	unsigned long      env_start;
-	unsigned long      env_end;
-	int                exit_code;
-} t_proc_stat;
+	char *specifier;
+	void *store;
+}
+g_stat_file_parsing_entries[] =
+{
+	{"%d",   &g_pid},
+	{"%s",   &g_comm},
+	{"%c",   &g_state},
+	{"%d",   &g_ppid},
+	{"%d",   &g_pgrp},
+	{"%d",   NULL},  // session
+	{"%d",   &g_tty_nr},
+	{"%d",   NULL},  // tpgid
+	{"%u",   &g_flags},
+	{"%lu",  NULL},  // minflt
+	{"%lu",  NULL},  // cminflt
+	{"%lu",  NULL},  // majflt
+	{"%lu",  NULL},  // cmajflt
+	{"%lu",  NULL},  // utime
+	{"%lu",  NULL},  // stime
+	{"%ld",  NULL},  // cutime
+	{"%ld",  NULL},  // cstime
+	{"%ld",  NULL},  // priority
+	{"%ld",  &g_nice},
+	{"%ld",  NULL},  // num_threads
+	{"%ld",  NULL},  // itrealvalue
+	{"%llu", &g_starttime},
+	{"%lu",  &g_vsize},
+	{"%ld",  NULL},  // rss
+	{"%lu",  NULL},  // rsslim
+	{"%lu",  NULL},  // startcode
+	{"%lu",  NULL},  // endcode
+	{"%lu",  NULL},  // startstack
+	{"%lu",  NULL},  // kstkesp
+	{"%lu",  NULL},  // kstkeip
+	{"%lu",  NULL},  // signal
+	{"%lu",  NULL},  // blocked
+	{"%lu",  NULL},  // sigignore
+	{"%lu",  NULL},  // sigcatch
+	{"%lu",  &g_wchan},
+	{"%lu",  NULL},  // nswap
+	{"%lu",  NULL},  // cnswap
+	{"%d",   NULL},  // exit_signal
+	{"%d",   NULL},  // processor
+	{"%u",   NULL},  // rt_priority
+	{"%llu", NULL},  // delayacct_blkio_ticks
+	{"%lu",  NULL},  // guest_time
+	{"%ld",  NULL},  // cguest_time
+	{"%lu",  NULL},  // end_data
+	{"%lu",  NULL},  // start_brk
+	{"%lu",  NULL},  // arg_start
+	{"%lu",  NULL},  // arg_end
+	{"%lu",  NULL},  // env_start
+	{"%lu",  NULL},  // env_end
+	{"%d",   NULL},  // exit_cod
+};
+*/
 
-int main(int argc, char **argv)
+void parse_stat_file(FILE *stat_file)
 {
-	field_infos_from_format(default_format);
+	fscanf(
+		stat_file,
+		"%*d %s %c %d %d %*d %d %*d %u %*lu %*lu %*lu %*lu %*lu %*lu %*ld %*ld %*ld "
+		"%ld %*ld %*ld %llu %lu %ld %*lu %*lu %*lu %*lu %*lu %*lu %*lu %*lu %*lu %*lu "
+		"%lu %*lu %*lu %*d %*d %*u %*llu %*lu %*ld %*lu %*lu %*lu %*lu %*lu %*lu %*d",
+		/* &g_pid, */
+		g_comm,
+		&g_state,
+		&g_ppid,
+		&g_pgrp,
+		&g_tty_nr,
+		&g_flags,
+		&g_nice,
+		&g_starttime,
+		&g_vsize,
+		&g_rss,
+		&g_wchan
+	);
+}
 
-	free(field_infos);
-	return;
 
+int main(int argc, char **argv)
+{
+	g_page_size = getpagesize();
+	g_clock_tick = sysconf(_SC_CLK_TCK);
+
+	char format[] = "sz vsz comm";
 
-	page_size = getpagesize();
-	clock_tick = sysconf(_SC_CLK_TCK);
+	fields_from_format(g_long_format);
+	print_fields_headers();
 
 	DIR *proc_dir = opendir(PROC_DIR);
 	if (proc_dir == NULL)
@@ -285,81 +367,25 @@ int main(int argc, char **argv)
 	struct dirent *proc_dir_entry = NULL;
 	while ((proc_dir_entry = readdir(proc_dir)) != NULL)
 	{
-		pid_t pid = 0;
-		if (sscanf(proc_dir_entry->d_name, "%d", &pid) != 1)
-			continue;
-
-		char file_path[PATH_MAX + 1] = {'\0'};
-		snprintf(file_path, PATH_MAX, "%s/%d/stat", PROC_DIR, pid);
-		FILE *stat_file = fopen(file_path, "r");
-		if (stat_file == NULL)
+		if (sscanf(proc_dir_entry->d_name, "%d", &g_pid) != 1)
 			continue;
-
-		t_proc_stat proc_stat;
-		fscanf(
-			stat_file,
-			"%d %s %c %d %d %d %d %d %u %lu %lu %lu %lu %lu %lu %ld %ld %ld %ld %ld %ld "
-			"%llu %lu %ld %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %lu %d %d %u "
-			"%llu %lu %ld %lu %lu %lu %lu %lu %lu %d",
-			&proc_stat.pid,
-			&proc_stat.comm,
-			&proc_stat.state,
-			&proc_stat.ppid,
-			&proc_stat.pgrp,
-			&proc_stat.session,
-			&proc_stat.tty_nr,
-			&proc_stat.tpgid,
-			&proc_stat.flags,
-			&proc_stat.minflt,
-			&proc_stat.cminflt,
-			&proc_stat.majflt,
-			&proc_stat.cmajflt,
-			&proc_stat.utime,
-			&proc_stat.stime,
-			&proc_stat.cutime,
-			&proc_stat.cstime,
-			&proc_stat.priority,
-			&proc_stat.nice,
-			&proc_stat.num_threads,
-			&proc_stat.itrealvalue,
-			&proc_stat.starttime,
-			&proc_stat.vsize,
-			&proc_stat.rss,
-			&proc_stat.rsslim,
-			&proc_stat.startcode,
-			&proc_stat.endcode,
-			&proc_stat.startstack,
-			&proc_stat.kstkesp,
-			&proc_stat.kstkeip,
-			&proc_stat.signal,
-			&proc_stat.blocked,
-			&proc_stat.sigignore,
-			&proc_stat.sigcatch,
-			&proc_stat.wchan,
-			&proc_stat.nswap,
-			&proc_stat.cnswap,
-			&proc_stat.exit_signal,
-			&proc_stat.processor,
-			&proc_stat.rt_priority,
-			&proc_stat.delayacct_blkio_ticks,
-			&proc_stat.guest_time,
-			&proc_stat.cguest_time,
-			&proc_stat.end_data,
-			&proc_stat.start_brk,
-			&proc_stat.arg_start,
-			&proc_stat.arg_end,
-			&proc_stat.env_start,
-			&proc_stat.env_end,
-			&proc_stat.exit_code
-		);
-
+		snprintf(g_file_path, PATH_MAX, PROC_DIR"/%d/stat", g_pid);
 		struct stat statbuf;
-		if (stat(file_path, &statbuf) == -1)
+		if (stat(g_file_path, &statbuf) == -1)
 			continue;
-
+		g_uid = statbuf.st_uid;
+		g_gid = statbuf.st_gid;
+		FILE *stat_file = fopen(g_file_path, "r");
+		if (stat_file == NULL)
+			continue;
+		parse_stat_file(stat_file);
+		for (size_t i = 0; i < g_fields_size; i++)
+		{
+			(g_fields[i]->print_func)(g_fields[i]);
+			fputc(' ', stdout);
+		}
 		fputc('\n', stdout);
-		break;
 	}
-
+	closedir(proc_dir);
 	return 0;
 }