diff options
| -rw-r--r-- | Makefile | 2 | ||||
| -rw-r--r-- | changelog | 9 | ||||
| -rw-r--r-- | inotail.c | 303 | ||||
| -rw-r--r-- | inotail.h | 36 |
4 files changed, 306 insertions, 44 deletions
@@ -4,7 +4,7 @@ # # Licensed under the terms of the GNU General Public License; version 2 or later. -VERSION = 0.6-pre0 +VERSION = 0.6 # Paths prefix = /usr/local @@ -1,3 +1,12 @@ +inotail 0.6 + + * Correctly handle tailing from pipes + * Do not try to seek on pipes when following (thanks Alexander Sulfrian) + * Handle file truncation in follow mode + * Various small fixes + + -- Tobias Klauser <tklauser@distanz.ch> 2008-08-31 21:15 + inotail 0.5 * Output verbose file headers correctly when used in a pipe @@ -32,22 +32,16 @@ #include <getopt.h> #include <sys/types.h> #include <sys/stat.h> - #include <sys/inotify.h> #include "inotail.h" #define PROGRAM_NAME "inotail" -#define DEFAULT_BUFFER_SIZE 4096 -/* inotify event buffer length for one file */ -#define INOTIFY_BUFLEN (4 * sizeof(struct inotify_event)) /* Print header with filename before tailing the file? */ static char verbose = 0; - /* Tailing relative to begin or end of file */ static char from_begin = 0; - /* Number of ignored files */ static int n_ignored = 0; @@ -62,7 +56,7 @@ static const struct option long_opts[] = { { NULL, 0, NULL, 0 } }; -static void *emalloc(size_t size) +static void *emalloc(const size_t size) { void *ret = malloc(size); @@ -94,7 +88,7 @@ static inline void setup_file(struct file_struct *f) { f->fd = f->i_watch = -1; f->size = 0; - f->blksize = DEFAULT_BUFFER_SIZE; + f->blksize = BUFSIZ; f->ignore = 0; } @@ -104,8 +98,10 @@ static void ignore_file(struct file_struct *f) close(f->fd); f->fd = -1; } - f->ignore = 1; - n_ignored++; + if (!f->ignore) { + f->ignore = 1; + n_ignored++; + } } static inline char *pretty_name(char *filename) @@ -236,27 +232,262 @@ static off_t bytes_to_offset(struct file_struct *f, unsigned long n_bytes) } else if ((off_t) n_bytes < f->size) offset = f->size - (off_t) n_bytes; + /* Otherwise offset stays 0 (begin of file) */ + return offset; } -static ssize_t tail_pipe(struct file_struct *f) +static int tail_pipe_from_begin(struct file_struct *f, unsigned long n_units, const char mode) { - ssize_t rc; - char *buf = emalloc(f->blksize); + int bytes_read = 0; + char buf[BUFSIZ]; - if (verbose) - write_header(f->name); + if (n_units) + n_units--; + + while (n_units > 0) { + if ((bytes_read = read(f->fd, buf, BUFSIZ)) <= 0) { + if (bytes_read < 0 && (errno == EINTR || errno == EAGAIN)) + continue; + else + return bytes_read; + } + + if (mode == M_LINES) { + int i; + ssize_t block_size = BUFSIZ; + + if (bytes_read < BUFSIZ) + block_size = bytes_read; + + for (i = 0; i < block_size; i++) { + if (buf[i] == '\n') { + if (--n_units == 0) + break; + } + } + + if (++i < block_size) + write(STDOUT_FILENO, &buf[i], bytes_read - i); + } else { + if ((unsigned long) bytes_read > n_units) { + write(STDOUT_FILENO, &buf[n_units], bytes_read - n_units); + bytes_read = n_units; + } + + n_units -= bytes_read; + } + } + + while ((bytes_read = read(f->fd, buf, BUFSIZ)) > 0) + write(STDOUT_FILENO, buf, (size_t) bytes_read); + + return 0; +} + +static int tail_pipe_lines(struct file_struct *f, unsigned long n_lines) +{ + struct line_buf *first, *last, *tmp; + int rc; + unsigned long total_lines = 0; + const char *p; + + if (from_begin) + return tail_pipe_from_begin(f, n_lines, M_LINES); + + if (n_lines == 0) + return 0; /* No lines to tail */ + + first = last = emalloc(sizeof(struct line_buf)); + first->n_bytes = first->n_lines = 0; + first->next = NULL; + tmp = emalloc(sizeof(struct line_buf)); + + while (1) { + if ((rc = read(f->fd, tmp->buf, BUFSIZ)) <= 0) { + if (rc < 0 && (errno == EINTR || errno == EAGAIN)) + continue; + else + break; /* No more data to read */ + } + tmp->n_bytes = rc; + tmp->n_lines = 0; + tmp->next = NULL; + p = tmp->buf; + + /* Count the lines in the current buffer */ + while ((p = memchr(p, '\n', tmp->buf + rc - p))) { + p++; + tmp->n_lines++; + } + total_lines += tmp->n_lines; + + /* Try to append to the previous buffer if there's enough free + * space + */ + if (tmp->n_bytes + last->n_bytes < BUFSIZ) { + memcpy(&last->buf[last->n_bytes], tmp->buf, tmp->n_bytes); + last->n_bytes += tmp->n_bytes; + last->n_lines += tmp->n_lines; + } else { + /* Add buffer to the list */ + last->next = tmp; + last = last->next; + /* We read more than n_lines lines, reuse the first + * buffer. + */ + if (total_lines - first->n_lines > n_lines) { + tmp = first; + total_lines -= first->n_lines; + first = first->next; + } else + tmp = emalloc(sizeof(struct line_buf)); + } + } + + free(tmp); + + if (rc < 0) { + fprintf(stderr, "Error: Could not read from %s\n", pretty_name(f->name)); + goto out; + } - /* We will just tail everything here */ - while ((rc = read(f->fd, buf, f->blksize)) > 0) { - if ((rc = write(STDOUT_FILENO, buf, (size_t) rc)) <= 0) { - /* e.g. when writing to a pipe which gets closed */ + if (last->n_bytes == 0) + goto out; + + /* Count incomplete lines */ + if (last->buf[last->n_bytes - 1] != '\n') { + last->n_lines++; + total_lines++; + } + + /* Skip unneeded buffers */ + for (tmp = first; total_lines - tmp->n_lines > n_lines; tmp = tmp->next) + total_lines -= tmp->n_lines; + + p = tmp->buf; + + /* Read too many lines, advance */ + if (total_lines > n_lines) { + unsigned long j; + for (j = total_lines - n_lines; j; --j) { + p = memchr(p, '\n', tmp->buf + tmp->n_bytes - p); + p++; + } + } + + if ((rc = write(STDOUT_FILENO, p, tmp->buf + tmp->n_bytes - p)) <= 0) { + /* e.g. when writing to a pipe which gets closed */ + fprintf(stderr, "Error: Could not write to stdout (%s)\n", strerror(errno)); + goto out; + } + + for (tmp = tmp->next; tmp; tmp = tmp->next) + if ((rc = write(STDOUT_FILENO, tmp->buf, tmp->n_bytes)) <= 0) { fprintf(stderr, "Error: Could not write to stdout (%s)\n", strerror(errno)); - break; + goto out; } + + rc = 0; +out: + while (first) { + tmp = first->next; + free(first); + first = tmp; + } + + return rc; +} + +/* TODO: Merge some parts (especially buffer handling) with tail_pipe_lines() */ +static int tail_pipe_bytes(struct file_struct *f, unsigned long n_bytes) +{ + struct char_buf *first, *last, *tmp; + int rc; + unsigned long total_bytes = 0; + unsigned long i = 0; /* Index into buffer */ + + if (from_begin) + return tail_pipe_from_begin(f, n_bytes, M_BYTES); + + /* XXX: Needed? */ + if (n_bytes == 0) + return 0; + + first = last = emalloc(sizeof(struct char_buf)); + first->n_bytes = 0; + first->next = NULL; + tmp = emalloc(sizeof(struct char_buf)); + + while(1) { + if ((rc = read(f->fd, tmp->buf, BUFSIZ)) <= 0) { + if (rc < 0 && (errno == EINTR || errno == EAGAIN)) + continue; + else + break; /* No more data to read */ + } + total_bytes += rc; + tmp->n_bytes = rc; + tmp->next = NULL; + + /* Try to append to the previous buffer if there's enough free + * space + */ + if (tmp->n_bytes + last->n_bytes < BUFSIZ) { + memcpy(&last->buf[last->n_bytes], tmp->buf, tmp->n_bytes); + last->n_bytes += tmp->n_bytes; + } else { + /* Add buffer to the list */ + last->next = tmp; + last = last->next; + /* We read more than n_bytess bytes, reuse the first + * buffer. + */ + if (total_bytes - first->n_bytes > n_bytes) { + tmp = first; + total_bytes -= first->n_bytes; + first = first->next; + } else + tmp = emalloc(sizeof(struct char_buf)); + } + } + + free(tmp); + + if (rc < 0) { + fprintf(stderr, "Error: Could not read from %s\n", pretty_name(f->name)); + goto out; + } + + /* Skip unneeded buffers */ + for (tmp = first; total_bytes - tmp->n_bytes > n_bytes; tmp = tmp->next) + total_bytes -= tmp->n_bytes; + + /* Read too many bytes, advance */ + if (total_bytes > n_bytes) + i = total_bytes - n_bytes; + + if ((rc = write(STDOUT_FILENO, &tmp->buf[i], tmp->n_bytes - i)) <= 0) { + /* e.g. when writing to a pipe which gets closed */ + fprintf(stderr, "Error: Could not write to stdout (%s)\n", strerror(errno)); + goto out; + } + + for (tmp = tmp->next; tmp; tmp = tmp->next) + if ((rc = write(STDOUT_FILENO, tmp->buf, tmp->n_bytes)) <= 0) { + fprintf(stderr, "Error: Could not write to stdout (%s)\n", strerror(errno)); + goto out; + } + + + rc = 0; +out: + while (first) { + tmp = first->next; + free(first); + first = tmp; } - free(buf); return rc; } @@ -273,26 +504,30 @@ static int tail_file(struct file_struct *f, unsigned long n_units, mode_t mode, f->fd = open(f->name, O_RDONLY); if (unlikely(f->fd < 0)) { fprintf(stderr, "Error: Could not open file '%s' (%s)\n", f->name, strerror(errno)); - ignore_file(f); return -1; } } if (fstat(f->fd, &finfo) < 0) { fprintf(stderr, "Error: Could not stat file '%s' (%s)\n", f->name, strerror(errno)); - ignore_file(f); return -1; } if (!IS_TAILABLE(finfo.st_mode)) { fprintf(stderr, "Error: '%s' of unsupported file type (%s)\n", f->name, strerror(errno)); - ignore_file(f); return -1; } /* Cannot seek on these */ - if (IS_PIPELIKE(finfo.st_mode) || f->fd == STDIN_FILENO) - return tail_pipe(f); + if (IS_PIPELIKE(finfo.st_mode) || f->fd == STDIN_FILENO) { + if (verbose) + write_header(f->name); + + if (mode == M_LINES) + return tail_pipe_lines(f, n_units); + else + return tail_pipe_bytes(f, n_units); + } f->size = finfo.st_size; f->blksize = finfo.st_blksize; /* TODO: Can this value be 0? */ @@ -303,19 +538,17 @@ static int tail_file(struct file_struct *f, unsigned long n_units, mode_t mode, offset = bytes_to_offset(f, n_units); /* We only get negative offsets on errors */ - if (unlikely(offset < 0)) { - ignore_file(f); + if (unlikely(offset < 0)) return -1; - } - - if (verbose) - write_header(f->name); if (lseek(f->fd, offset, SEEK_SET) == (off_t) -1) { fprintf(stderr, "Error: Could not seek in file '%s' (%s)\n", f->name, strerror(errno)); return -1; } + if (verbose) + write_header(f->name); + buf = emalloc(f->blksize); while ((bytes_read = read(f->fd, buf, f->blksize)) > 0) @@ -357,7 +590,7 @@ static int handle_inotify_event(struct inotify_event *inev, struct file_struct * } /* Seek to old file size */ - if ((ret = lseek(f->fd, f->size, SEEK_SET)) == (off_t) -1) { + if (!IS_PIPELIKE(finfo.st_mode) && (ret = lseek(f->fd, f->size, SEEK_SET)) == (off_t) -1) { fprintf(stderr, "Error: Could not seek in file '%s' (%s)\n", f->name, strerror(errno)); goto ignore; } @@ -378,6 +611,8 @@ static int handle_inotify_event(struct inotify_event *inev, struct file_struct * return 0; } else if (inev->mask & IN_UNMOUNT) { fprintf(stderr, "Device containing file '%s' unmounted.\n", f->name); + } else if (inev->mask & IN_IGNORED) { + return 0; } ignore: @@ -462,7 +697,7 @@ int main(int argc, char **argv) int i, c, ret = 0; int n_files; unsigned long n_units = DEFAULT_N_LINES; - mode_t mode = M_LINES; + char mode = M_LINES; char forever = 0; char **filenames; struct file_struct *files = NULL; @@ -8,12 +8,15 @@ #define _INOTAIL_H #include <sys/types.h> +#include "inotify.h" -/* Number of items to tail. */ -#define DEFAULT_N_LINES 10 +#define DEFAULT_N_LINES 10 /* Number of items to tail. */ + +/* inotify event buffer length for one file */ +#define INOTIFY_BUFLEN (4 * sizeof(struct inotify_event)) /* tail modes */ -typedef enum { M_LINES, M_BYTES } mode_t; +enum tail_mode { M_LINES, M_BYTES }; /* Every tailed file is represented as a file_struct */ struct file_struct { @@ -25,6 +28,21 @@ struct file_struct { int i_watch; /* Inotify watch associated with file_struct */ }; +/* struct for linked list of buffers/lines in tail_pipe_lines */ +struct line_buf { + char buf[BUFSIZ]; + size_t n_lines; + size_t n_bytes; + struct line_buf *next; +}; + +/* struct for linked list of byte buffers in tail_pipe_bytes */ +struct char_buf { + char buf[BUFSIZ]; + size_t n_bytes; + struct char_buf *next; +}; + #define IS_PIPELIKE(mode) \ (S_ISFIFO(mode) || S_ISSOCK(mode)) @@ -34,16 +52,16 @@ struct file_struct { #define is_digit(c) ((c) >= '0' && (c) <= '9') -#ifdef DEBUG -# define dprintf(fmt, args...) fprintf(stderr, fmt, ##args) -#else -# define dprintf(fmt, args...) -#endif /* DEBUG */ - #ifdef __GNUC__ # define unlikely(x) __builtin_expect(!!(x), 0) #else # define unlikely(x) (x) #endif /* __GNUC__ */ +#ifdef DEBUG +# define dprintf(fmt, args...) fprintf(stderr, fmt, ##args) +#else +# define dprintf(fmt, args...) +#endif /* DEBUG */ + #endif /* _INOTAIL_H */ |