Come ottenere il percorso del file corrente (pwd) in Linux da C?

La semplice apertura e lettura delle directory non modifica la directory di lavoro corrente. Tuttavia, la modifica della directory nel tuo programma lo farà.

per riferimento,

#include <unistd.h>
#include <stdio.h>

int main() {
    char cwd[1024];
    chdir("/path/to/change/directory/to");
    getcwd(cwd, sizeof(cwd));
    printf("Current working dir: %s\n", cwd);
}

Per i sistemi POSIX ho trovato tre soluzioni:

Ottieni valore da una variabile di ambiente "PWD"

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

#ifdef __unix__
    #define IS_POSIX 1
#else
    #define IS_POSIX 0
#endif


int main (int argv, char **argc)
{
    if (IS_POSIX == 1) {
        puts("Path info by use environment variable PWD:");
        printf("\tWorkdir: %s\n", getenv("PWD"));
        printf("\tFilepath: %s/%s\n", getenv("PWD"), __FILE__);
    }
    return 0;
}

Risultato:

Path info by use environment variable PWD:
    Workdir: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils
    Filepath: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils/main.c

Usa getcwd()

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

#ifdef __unix__
    #define IS_POSIX 1
    #include <unistd.h>
#else
    #define IS_POSIX 0
#endif


int main (int argv, char **argc)
{
    if (IS_POSIX == 1) {
        char cwd[1024];
        getcwd(cwd, sizeof(cwd));
        puts("Path info by use getcwd():");
        printf("\tWorkdir: %s\n", cwd);
        printf("\tFilepath: %s/%s\n", cwd, __FILE__);
    }
    return 0;
}

Risultato

Path info by use getcwd():
    Workdir: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils
    Filepath: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils/main.c

Esegui il comando di sistema "pwd" e leggi l'output

#ifdef __unix__
    #define IS_POSIX 1
    #define _BSD_SOURCE
#else
    #define IS_POSIX 0
#endif

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


int main (int argv, char **argc)
{
    if (IS_POSIX == 1) {
        char buffer[500];
        FILE *output;

        // read output of a command
        output = popen("/bin/pwd", "r");
        char *pwd = fgets(buffer, sizeof(buffer), output);

        // strip '\n' on ending of a line
        pwd = strtok(pwd, "\n");

        puts("Path info by execute shell command 'pwd':");
        printf("\tWorkdir: %s\n", pwd);
        printf("\tFilepath: %s/%s\n", pwd, __FILE__);
    }
    return 0;
}

Risultato:

Path info by execute shell command 'pwd':
    Workdir: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils
    Filepath: /media/setivolkylany/WorkDisk/Programming/Projects/c-utils/main.c

Puoi usare chdir(2) per cambiare dir da C, quindi system("pwd"); ti darà qualunque directory tu chdir 'ed a.

L'equivalente in C del pwd -il comando è getcwd(3).