diff options
| -rw-r--r-- | inotail.c | 59 |
1 files changed, 46 insertions, 13 deletions
@@ -110,8 +110,7 @@ static off_t lines_to_offset(struct file_struct *f, unsigned int n_lines) n_lines--; if (n_lines == 0) { - /* We don't want the first \n */ - offset += i + 1; + offset += i + 1; /* We don't want the first \n */ break; } } @@ -121,6 +120,20 @@ static off_t lines_to_offset(struct file_struct *f, unsigned int n_lines) return offset; } +static int bytes_to_offset(struct file_struct *f, int n_lines) +{ + int ret = f->st_size - n_lines; + + return (ret < 0 ? 0 : ret); +} + +/* We will just tail everything here */ +static int tail_pipe(struct file_struct *f) +{ + dprintf(" Trying to tail from '%s'\n", f->name); + return 0; +} + static int tail_file(struct file_struct *f, int n_lines, char mode) { ssize_t rc = 0; @@ -128,10 +141,14 @@ static int tail_file(struct file_struct *f, int n_lines, char mode) char buf[BUFFER_SIZE]; struct stat finfo; - f->fd = open(f->name, O_RDONLY); - if (f->fd < 0) { - fprintf(stderr, "Error: Could not open file '%s' (%s)\n", f->name, strerror(errno)); - return -1; + if (strncmp(f->name, "-", 1) == 0) + f->fd = STDIN_FILENO; + else { + f->fd = open(f->name, O_RDONLY); + if (f->fd < 0) { + fprintf(stderr, "Error: Could not open file '%s' (%s)\n", f->name, strerror(errno)); + return -1; + } } if (fstat(f->fd, &finfo) < 0) { @@ -140,13 +157,18 @@ static int tail_file(struct file_struct *f, int n_lines, char mode) return -1; } + /* We cannot seek on these */ + if (!S_ISREG(finfo.st_mode) || f->fd == STDIN_FILENO) + return tail_pipe(f); + f->st_size = finfo.st_size; if (mode == M_LINES) offset = lines_to_offset(f, n_lines); - else /* Bytewise tail */ - offset = f->st_size - n_lines; + else /* Bytewise tail, n_lines is number of bytes here */ + offset = bytes_to_offset(f, n_lines); + /* We only get negative offsets on errors */ if (offset < 0) return -1; @@ -155,13 +177,14 @@ static int tail_file(struct file_struct *f, int n_lines, char mode) lseek(f->fd, offset, SEEK_SET); - while ((rc = read(f->fd, &buf, BUFFER_SIZE)) != 0) { + while ((rc = read(f->fd, &buf, BUFFER_SIZE)) > 0) { dprintf(" f->st_size - offset: %lu\n", f->st_size - offset); dprintf(" rc: %d\n", rc); write(STDOUT_FILENO, buf, (size_t) rc); } - close(f->fd); + if (close(f->fd) < 0) + fprintf(stderr, "Error: Could not close file '%s' (%s)\n", f->name, strerror(errno)); return 0; } @@ -321,9 +344,19 @@ int main(int argc, char **argv) n_files = argc - opt; filenames = argv + opt; } else { - /* For now, reading from stdin will be implemented later (tm) */ - /* XXX: This is not like GNU tail behaves! */ - usage(EXIT_FAILURE); + /* It must be stdin then */ + static char *dummy_stdin = "-"; + n_files++; + filenames = &dummy_stdin; + + /* POSIX says that -f is ignored if no file operand is + specified and standard input is a pipe. */ + if (forever) { + struct stat finfo; + if (fstat(STDIN_FILENO, &finfo) == 0 + && (S_ISFIFO(finfo.st_mode) || S_ISSOCK(finfo.st_mode))) + forever = 0; + } } files = malloc(n_files * sizeof(struct file_struct)); |