68 lines
1.1 KiB
C
68 lines
1.1 KiB
C
#include <fcntl.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <dirent.h>
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#include <errno.h>
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int open_file(const char *path) {
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int fd = open(path, O_RDONLY);
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if (fd < 0) {
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fprintf(stderr, "ps: %s: %s\n", path, strerror(errno));
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return -1;
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}
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return fd;
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}
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int pscan(const char *pid) {
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char path[PATH_MAX + 1];
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char cmdline[PATH_MAX + 1];
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/* Arguments */
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snprintf(path, sizeof(path), "/proc/%s/cmdline", pid);
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int fd = open_file(path);
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if (fd == -1)
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return 1;
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read(fd, cmdline, sizeof(cmdline));
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close(fd);
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printf("%5s %5s\n", pid, cmdline);
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return 0;
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}
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int main(int argc, char **argv) {
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int opt;
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while ((opt = getopt(argc, argv, "o:")) != -1) {
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switch (opt) {
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case 'o':
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break;
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default:
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printf("ps [o] [PID]\n\t-o Options (nice, tty, cmd, pid, nice)\n");
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return 0;
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}
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}
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DIR *dp = opendir("/proc");
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if (dp == NULL) {
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fprintf(stderr, "ps: /proc: %s\n", strerror(errno));
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return 1;
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}
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printf("PID CMD\n");
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int ret = 0;
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struct dirent *ep;
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while ((ep = readdir(dp)) != NULL)
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if (atoi(ep->d_name))
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if (pscan(ep->d_name))
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ret = 1;
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closedir(dp);
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return ret;
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}
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