1 /** F77 NOTE: the getcwd() routine should be in libc.a ! **/ 2 /* 3 * return name of working (current) directory 4 */ 5 #include <stdio.h> 6 #include <sys/param.h> 7 #include <sys/stat.h> 8 #include <sys/dir.h> 9 10 static char slash[] = "/"; 11 static char dot[] = "."; 12 static char dotdot[] = ".."; 13 static char name[128]; 14 15 char * 16 getcwd() 17 { 18 int rdev, rino; 19 int fd; 20 struct stat d, dd; 21 struct direct dir; 22 char *prepend(); 23 char *namep = &name[(sizeof name)-1]; 24 25 *namep = '\0'; 26 stat(slash, &d); 27 rdev = d.st_dev; 28 rino = d.st_ino; 29 for (;;) 30 { 31 stat(dot, &d); 32 if (d.st_ino == rino && d.st_dev == rdev) 33 { 34 if (*namep == '\0') /* rootdir is a special case */ 35 namep = prepend(namep, slash); 36 chdir(namep); 37 return(namep); 38 } 39 if ((fd = open(dotdot,0)) < 0) 40 { 41 chdir(prepend(namep, dot)); 42 return((char *)0); 43 } 44 chdir(dotdot); 45 fstat(fd, &dd); 46 if(d.st_dev == dd.st_dev) 47 { 48 if(d.st_ino == dd.st_ino) 49 { 50 close(fd); 51 if (*namep == '\0') /* root is a special case */ 52 namep = prepend(namep, slash); 53 chdir(namep); 54 return(namep); 55 } 56 do 57 { 58 if (read(fd, (char *)&dir, sizeof(dir)) < sizeof(dir)) 59 { 60 close(fd); 61 chdir(prepend(namep, dot)); 62 return((char *)0); 63 } 64 } while (dir.d_ino != d.st_ino); 65 } 66 else do 67 { 68 if(read(fd, (char *)&dir, sizeof(dir)) < sizeof(dir)) 69 { 70 close(fd); 71 chdir(prepend(namep, dot)); 72 return((char *)0); 73 } 74 stat(dir.d_name, &dd); 75 } while(dd.st_ino != d.st_ino || dd.st_dev != d.st_dev); 76 close(fd); 77 namep = prepend(prepend(namep, dir.d_name), slash); 78 } 79 } 80 81 char * 82 prepend(p, n) 83 char *p; 84 char *n; 85 { 86 int i = 0; 87 88 while (i < DIRSIZ && *n) 89 { 90 n++; i++; 91 } 92 while (i--) 93 *--p = *--n; 94 return(p); 95 } 96 97 /* 98 char id_getcwd[] = "@(#)getcwd_.c 1.3"; 99 * Get pathname of current working directory. 100 * 101 * calling sequence: 102 * character*128 path 103 * ierr = getcwd(path) 104 * where: 105 * path will receive the pathname of the current working directory. 106 * ierr will be 0 if successful, a system error code otherwise. 107 */ 108 109 extern int errno; 110 111 long 112 getcwd_(path, len) 113 char *path; 114 long len; 115 { 116 char *p; 117 118 p = getcwd(); 119 if (p) 120 { 121 b_char(p, path, len); 122 return(0L); 123 } 124 return((long)errno); 125 } 126