utils.c

#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#include <unistd.h>
#include <sys/wait.h>

#include "logos.h"
#include "utils.h"

// copy an ascii art from file to mem
void *file_to_logo(char *file) {
    FILE *fp = fopen(file, "r");
    if(fp == NULL)
        return NULL;

    /* 
     * mem is assumed to be a 10 KiB buffer, aka 10240 B.
     * this will be filled in with up to 64 lines,
     * each of which can be up to 160 bytes long.
     * (LINE_LEN * LINE_NUM) should equal this size.
     * Check out main.c, line 132
    */
    #define LINE_LEN 256
    #define LINE_NUM 40

    // where the final logo is saved
    static char *logo[LINE_NUM + 1];
    char *mem = NULL;

    char *buffer = NULL;
    size_t len = 0;
    size_t line_len;
    int i = 0;

    // setting the correct color (or eventually the first line)

    line_len = getline(&buffer, &len, fp);  // save the first line to buffer
    if(line_len == (size_t)-1)              // getline returns -1 in case of error
        return NULL;

    if(buffer[line_len-1] == '\n')
        buffer[line_len-1] = 0;

    config.color[0] = 0;

    const char *colors[][2] = {
        {"black", "\033[30m"},
        {"red", "\033[31m"},
        {"green", "\033[32m"},
        {"yellow", "\033[33m"},
        {"blue", "\033[34m"},
        {"purple", "\033[35m"},
        {"cyan", "\033[36m"},
        {"gray", "\033[90m"},
        {"white", "\033[37m"},
    };

    for(int j = 0; j < 9; ++j)
        if(strcmp(buffer, *colors[j]) == 0)
            strcpy(config.color, colors[j][1]);

    mem = malloc(10240);
    memset(mem, 0, 1024);

    if(config.color[0] == 0) {
        unescape(buffer);

        logo[i+2] = mem + i*LINE_LEN;
        strncpy((char*)logo[i+2], buffer, LINE_LEN);

        ++i;
    }

    // for every remaining line of the logo...
    while((line_len = getline(&buffer, &len, fp)) != (size_t)-1 && i < LINE_NUM) {
        if(buffer[line_len-1] == '\n')
            buffer[line_len-1] = 0;

        unescape(buffer);

        logo[i+2] = mem + i*LINE_LEN;
        strncpy(logo[i+2], buffer, LINE_LEN);
        
        ++i;
    }

    // cleaning up
    fclose(fp);
    free(buffer);

    // set up the logo metadata;
    logo[0] = "custom";  // logo ID
    
    // the array of lines is NULL-terminated;
    logo[i+2] = NULL;

    // finally, the logo can be saved
    config.logo = logo;

    return mem;
}

// add a module containing id to array
void add_module(struct Module *array, char *id) {
    struct Module *new = malloc(sizeof(struct Module));
    struct Module *last = array;

    for(struct Module *current = array; current->next; current = current->next)
        last = current->next;
    
    last->next = new;

    new->id = malloc(strlen(id)+1);
    strcpy(new->id, id);

    new->label = NULL;
    new->func = NULL;

    new->next = NULL;
}

// free every module in array
void destroy_array(struct Module *array) {
    struct Module *current = array;
    struct Module *next;

    while(current) {
        next = current->next;
        free(current->id);
        free(current);
        current = next;
    }
}

// print a certain line of the logo
void get_logo_line(char *dest, unsigned *line) {
    if(config.logo == NULL || dest == NULL || *line < 1)
        return;
        
    if(config.logo[(*line)+1]) {
        ++(*line);
        strcat(dest, config.logo[*line]);
    }
    else {
        for(size_t i = 0; i < strlen_real(config.logo[2]); ++i)
            strcat(dest, " ");
    }
}

// print no more than maxlen visible characters of line
void print_line(char *line, const size_t maxlen) {
    if(bold)
        fputs("\033[1m", stdout);

    bool escaping = false;
    int unicode = 0;

    for(size_t i = 0, len = 0; len < maxlen && i < strlen(line); ++i) {
            putc(line[i], stdout);

            if(line[i] == '\n')
                break;
            else if(line[i] == '\033')
                escaping = true;
            else if(line[i] & 0x80) {       // is the 1st bit 1?
                if(line[i] & 0x40) {        // is the 2nd bit 1?
                    if(line[i] & 0x20) {    // is the 3rd bit 1?
                        if(line[i] & 0x10)  // is the 4th bit 1?
                            unicode = 3;    // first of 4 unicode bytes (0b11110xxx)
                        else
                            unicode = 2;    // first of 3 unicode bytes (0b1110xxxx)
                    }
                    else
                        unicode = 1;        // first of 2 unicode bytes (0b110xxxxx)
                }
                else if(unicode-- == 1)     // unicode continuation byte (0b10xxxxxx)
                    ++len;
            }
            else {
                // look mom, I just wanted to try to write some branchless code

                // this line is a bit weird
                // ++len <=> escaping == 0
                len += (size_t)1-escaping;

                /* m is found     and escaping     => escaping = 0
                 * m is found     and not escaping => escaping = 0
                 * m is not found and escaping     => escaping = 1
                 * m is not found and not escaping => escaping = 0
                 */
                escaping = (line[i] != 'm') && escaping;
            }
        }

    fputs("\033[0m\n", stdout);
}

// a return code of 0 means that the option was parsed successfully
int parse_config_str(const char* source, const char *field, char *dest, const size_t maxlen) {
    char *ptr, *end;

    // looks for the keyword
    ptr = strstr(source, field);
    if(ptr == NULL)
        return 1;

    // looks for the opening "
    ptr = strchr(ptr, '"');
    if(ptr == NULL)
        return 1;

    // checks whether the string continues after
    ++ptr;
    if(*ptr == 0)
        return 1;

    // looks for the closing "
    end = strchr(ptr, '"');
    if(end == NULL)
        return 1;

    // copies the option
    *end = 0;
    
    size_t len = strlen(ptr);
    if(len+1 > maxlen) {
        memcpy(dest, ptr, maxlen);
        dest[maxlen-1] = 0;
    }
    else
        memcpy(dest, ptr, len+1);


    *end = '"';

    return 0;
}

// a return code of 0 means that the option was parsed successfully
int parse_config_int(const char *source, const char *field, int *dest, const unsigned max) {
    char *ptr, *end;

    // looks for the keyword
    ptr = strstr(source, field);
    if(ptr == NULL)
        return 1;

    // looks for the opening "
    ptr = strchr(ptr, '"');
    if(ptr == NULL)
        return 1;
        
    // checks whether the string continues after
    ++ptr;
    if(*ptr == 0)
        return 1;

    // looks for the closing "
    end = strchr(ptr, '"');
    if(end == NULL)
        return 1;

    // copies the option
    *end = 0;
    int num = atoi(ptr);
    *end = '"';

    if((unsigned)num > max)
        return 1;

    *dest =  num;

    return 0;
}

// a return code of 0 means that the option was parsed successfully
int parse_config_bool(const char *source, const char *field, bool *dest) {
    char *ptr, *end;

    // looks for the keyword
    ptr = strstr(source, field);
    if(ptr == NULL)
        return 1;

    // looks for the opening "
    ptr = strchr(ptr, '"');
    if(ptr == NULL)
        return 1;
        
    // checks whether the string continues after
    ++ptr;
    if(*ptr == 0)
        return 1;

    // looks for the closing "
    end = strchr(ptr, '"');
    if(end == NULL)
        return 1;

    // copies the option
    *end = 0;
    *dest = strcmp(ptr, "false");
    *end = '"';

    return 0;
}

// remove comments, aka from start to the end of the line
void uncomment(char *str, const char start) {
    char *ptr = str, *ptr2;
    while((ptr = strchr(ptr, start))) {
        // when it is between two " (aka the number of " before it is odd)
        int counter = 0;
        ptr2 = str;
        while((ptr2 = strchr(ptr2, '"')) && ptr2 < ptr) {
            ++ptr2;
            ++counter;
        }
        if(counter&1) {
            ++ptr;
            continue;
        }

        ptr2 = strchr(ptr, '\n');
        
        if(ptr2 == NULL) {
            *ptr = 0;
            break;
        }

        memmove(ptr, ptr2+1, strlen(ptr2));
    }
}

// parse the provided config file
void parse_config(const char *file, struct Module *modules, void **ascii_ptr, bool *default_bold, char *default_color, char *default_logo) {
    FILE *fp = fopen(file, "r");

    if(fp == NULL)
        return;

    fseek(fp, 0, SEEK_END);
    size_t len = (size_t)ftell(fp);
    rewind(fp);
    
    char *conf = malloc(len+1);
    conf[fread(conf, 1, len, fp)] = 0;
    fclose(fp);

    // used later
    char *ptr, *ptr2;

    // remove comments
    uncomment(conf, '#');
    uncomment(conf, ';');

    // handle escape sequences
    unescape(conf);

    // GENERAL OPTIONS

    // ascii art
    char path[96] = "";
    parse_config_str(conf, "ascii_art", path, sizeof(path));
    if(path[0])
        *ascii_ptr = file_to_logo(path);
    
    // logo
    char logo[32] = "";
    parse_config_str(conf, "logo", logo, sizeof(logo));
    if(logo[0]) {
        for(size_t i = 0; i < sizeof(logos)/sizeof(logos[0]); ++i)
            if(strcmp(logos[i][0], logo) == 0) {
                config.logo = logos[i];
                strcpy(default_logo, logos[i][0]);
                strcpy(config.color, logos[i][1]);
            }
    }

    // color
    char color[16] = "";
    parse_config_str(conf, "default_color", color, sizeof(color));
    if(color[0]) {
        const char *colors[][2] = {
            {"black", "\033[30m"},
            {"red", "\033[31m"},
            {"green", "\033[32m"},
            {"yellow", "\033[33m"},
            {"blue", "\033[34m"},
            {"purple", "\033[35m"},
            {"cyan", "\033[36m"},
            {"gray", "\033[90m"},
            {"white", "\033[37m"},
        };

        for(int i = 0; i < 9; ++i)
            if(strcmp(color, *colors[i]) == 0) {
                strcpy(config.color, colors[i][1]);
                strcpy(default_color, colors[i][1]);
            }
    }

    // dash
    parse_config_str(conf, "dash", config.dash, sizeof(config.dash));

    // spacing
    parse_config_int(conf, "spacing", &config.spacing, 64);

    // separator
    parse_config_str(conf, "separator_character", config.separator, sizeof(config.separator));

    // BOOLEAN OPTIONS (check utils.h)

    const char *booleanOptions[] = {
        "align_infos",
        "bold",
        "colored_title",
        "os_arch",
        "kernel_short",
        "desktop_type",
        "shell_path",
        "term_ssh",
        "pkg_mgr",
        "pkg_pacman",
        "pkg_dpkg",
        "pkg_rpm",
        "pkg_flatpak",
        "pkg_snap",
        "pkg_brew",
        "pkg_pip",
        "cpu_brand",
        "cpu_freq",
        "cpu_count",
        "gpu_brand",
        "mem_perc",
        "loc_localhost",
        "loc_docker",
        "pwd_path",
        "kernel_type",
        "col_background",
        "bat_status"
    };

    bool buffer;
    for(size_t i = 0; i < sizeof(booleanOptions)/sizeof(booleanOptions[0]); ++i) {
        if(parse_config_bool(conf, booleanOptions[i], &buffer) == 0) {
            if(buffer)
                config.options |= ((uint64_t)1 << i);
            else
                config.options &= ~((uint64_t)1 << i);
        }
    }
    *default_bold = bold;

    // OTHER MODULE-RELATED OPTIONS

    parse_config_int(conf, "gpu_index", &config.gpu_index, 3);

    parse_config_str(conf, "date_format", config.date_format, sizeof(config.date_format));

    parse_config_str(conf, "col_block_str", config.col_block_str, sizeof(config.col_block_str));

    // LABELS

    struct Prefix {
        char *option;
        const char *config_name;
    };
    
    struct Prefix prefixes[] = {
    //  {config.module_prefix, "module_prefix"}
        {config.separator_prefix, "separator_prefix"},
        {config.spacing_prefix, "spacing_prefix"},
        {config.title_prefix, "title_prefix"},
        {config.user_prefix, "user_prefix"},
        {config.hostname_prefix, "hostname_prefix"},
        {config.uptime_prefix, "uptime_prefix"},
        {config.os_prefix, "os_prefix"},
        {config.kernel_prefix, "kernel_prefix"},
        {config.desktop_prefix, "desktop_prefix"},
        {config.gtk_theme_prefix, "gtk_theme_prefix"},
        {config.icon_theme_prefix, "icon_theme_prefix"},
        {config.cursor_theme_prefix, "cursor_theme_prefix"},
        {config.shell_prefix, "shell_prefix"},
        {config.login_shell_prefix, "login_shell_prefix"},
        {config.term_prefix, "term_prefix"},
        {config.pkg_prefix, "pkg_prefix"},
        {config.host_prefix, "host_prefix"},
        {config.bios_prefix, "bios_prefix"},
        {config.cpu_prefix, "cpu_prefix"},
        {config.gpu_prefix, "gpu_prefix"},
        {config.mem_prefix, "mem_prefix"},
        {config.pub_prefix, "pub_prefix"},
        {config.loc_prefix, "loc_prefix"},
        {config.pwd_prefix, "pwd_prefix"},
        {config.date_prefix, "date_prefix"},
        {config.bat_prefix, "bat_prefix"},
        {config.colors_prefix, "colors_prefix"},
        {config.light_colors_prefix, "colors_light_prefix"},
    };

    for(size_t i = 0; i < sizeof(prefixes)/sizeof(prefixes[0]); ++i)
        parse_config_str(conf, prefixes[i].config_name, prefixes[i].option, 64);

    // MODULES
    
    ptr = strstr(conf, "modules");
    if(ptr == NULL) {
        free(conf);
        return;
    }

    ptr2 = strchr(ptr, '{');
    if(ptr2 == NULL) {
        free(conf);
        return;
    }

    char *end = strchr(ptr2, '}');
    if(end == NULL) {
        free(conf);
        return;
    }
    *end = 0;

    while((ptr = strchr(ptr2, '"'))) {
        ++ptr;

        ptr2 = strchr(ptr, '"');
        if(ptr2 == NULL) {
            free(conf);
            return;
        }
        *ptr2 = 0;

        add_module(modules, ptr);

     // *ptr2 = '"';
        ++ptr2;
    }

 // *end = '}';

    free(conf);
}

// check every '\' in str and unescape "\\" "\n" "\e" "\033"
void unescape(char *str) {
    while((str = strchr(str, '\\'))) {
        switch(str[1]) {
            case 'e':
                memmove(str, str+1, strlen(str));
                *str = '\033';
                break;
            case '0':
                if(str[2] == '3' && str[3] == '3') {
                    memmove(str, str+3, strlen(str+2));
                    *str = '\033';
                }
                break;
            case 'n':
                memmove(str, str+1, strlen(str));
                *str = '\n';
                break;
            default:    // takes care of "\\" and any other sort of "\X"
                memmove(str, str+1, strlen(str));
                ++str;
                break;
        }
    }
}

int exec_cmd(char *buf, size_t len, char *const *argv) {
    int stderr_pipes[2];
    int stdout_pipes[2];

    if(pipe(stdout_pipes) != 0 || pipe(stderr_pipes) != 0)
        return 1;

    if(fork() == 0) {
        close(stdout_pipes[0]);
        close(stderr_pipes[0]);
        dup2(stdout_pipes[1], STDOUT_FILENO);
        dup2(stderr_pipes[1], STDERR_FILENO);

        execvp(argv[0], argv);
    }

    wait(0);

    close(stderr_pipes[0]);
    close(stderr_pipes[1]);

    close(stdout_pipes[1]);
    buf[read(stdout_pipes[0], buf, len) - 1] = 0;
    close(stdout_pipes[0]);

    return 0;
}

// get the printed length of a string (not how big it is in memory)
__attribute__((pure)) size_t strlen_real(const char *str) {
    if(str == NULL)
        return 0;

    size_t len = 0;

    bool escaping = false;

    // determine how long the printed string is (same logic as in print_line, utils.c)
    while(*str) {
        if(*str == '\n')
            break;

        // unicode continuation byte 0x10xxxxxx
        if(*str & 0x80 && (*str & 0x40) == 0) {
            ++str;
            continue;
        }

        if(*str != '\033') {
            len += (size_t)1-escaping;

            escaping = (*str != 'm') && escaping;
        }
        else
            escaping = true;
        
        ++str;
    }

    return len;
}