linux c 查找进程

#include <stdio.h>
#include <dirent.h>
#include <string.h>
#include <ctype.h>

int is_numeric(const char *str) {
    while (*str) {
        if (!isdigit(*str)) {
            return 0;
        }
        str++;
    }
    return 1;
}

void find_process_by_name(const char *process_name) {
    DIR *dir;
    struct dirent *entry;

    dir = opendir("/proc");
    if (dir == NULL) {
        perror("opendir");
        return;
    }

    while ((entry = readdir(dir)) != NULL) {
        if (is_numeric(entry->d_name)) {
            char path[256];
            snprintf(path, sizeof(path), "/proc/%s/comm", entry->d_name);
            FILE *fp = fopen(path, "r");
            if (fp) {
                char name[256];
                if (fgets(name, sizeof(name), fp)) {
                    // Remove newline character
                    name[strcspn(name, "
")] = 0;
                    if (strcmp(name, process_name) == 0) {
                        printf("Process %s found with PID %s
", process_name, entry->d_name);
                    }
                }
                fclose(fp);
            }
        }
    }

    closedir(dir);
}

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: %s <process_name>
", argv[0]);
        return 1;
    }

    find_process_by_name(argv[1]);
    return 0;
}