diff options
Diffstat (limited to 'inotail.c')
| -rw-r--r-- | inotail.c | 82 |
1 files changed, 63 insertions, 19 deletions
@@ -40,7 +40,7 @@ #include "inotail.h" #define PROGRAM_NAME "inotail" -#define BUFFER_SIZE 4096 +#define DEFAULT_BUFFER_SIZE 4096 /* inotify event buffer length for one file */ #define INOTIFY_BUFLEN (4 * sizeof(struct inotify_event)) @@ -84,6 +84,7 @@ static inline void setup_file(struct file_struct *f) { f->fd = -1; f->st_size = 0; + f->st_blksize = DEFAULT_BUFFER_SIZE; f->ignore = 0; f->i_watch = -1; } @@ -115,18 +116,34 @@ static void write_header(char *filename) last = filename; } +static char *alloc_buffer(struct file_struct *f) +{ + char *buf; + + buf = malloc(f->st_blksize); + if (!buf) { + fprintf(stderr, "Error: Failed to allocate memory (%s)\n", strerror(errno)); + exit(EXIT_FAILURE); + } + + return buf; +} + static off_t lines_to_offset_from_end(struct file_struct *f, unsigned long n_lines) { - char buf[BUFFER_SIZE]; + char *buf; off_t offset = f->st_size; + ssize_t buffer_size = f->st_blksize; + + buf = alloc_buffer(f); n_lines++; /* We also count the last \n */ while (offset > 0 && n_lines > 0) { int i; - ssize_t rc, block_size = BUFFER_SIZE; /* Size of the current block we're reading */ + ssize_t rc, block_size = buffer_size; /* Size of the current block we're reading */ - if (offset < BUFFER_SIZE) + if (offset < buffer_size) block_size = offset; /* Start of current block */ @@ -137,25 +154,31 @@ static off_t lines_to_offset_from_end(struct file_struct *f, unsigned long n_lin rc = read(f->fd, buf, block_size); if (unlikely(rc < 0)) { fprintf(stderr, "Error: Could not read from file '%s' (%s)\n", f->name, strerror(errno)); + free(buf); return -1; } for (i = block_size - 1; i > 0; i--) { if (buf[i] == '\n') { - if (--n_lines == 0) + if (--n_lines == 0) { + free(buf); return offset += i + 1; /* We don't want the first \n */ + } } } } + free(buf); return offset; } static off_t lines_to_offset_from_begin(struct file_struct *f, unsigned long n_lines) { - char buf[BUFFER_SIZE]; + char *buf; off_t offset = 0; + buf = alloc_buffer(f); + /* tail everything for 'inotail -n +0' */ if (n_lines == 0) return 0; @@ -164,27 +187,31 @@ static off_t lines_to_offset_from_begin(struct file_struct *f, unsigned long n_l while (offset <= f->st_size && n_lines > 0) { int i; - ssize_t rc, block_size = BUFFER_SIZE; + ssize_t rc, block_size = f->st_blksize; lseek(f->fd, offset, SEEK_SET); rc = read(f->fd, buf, block_size); if (unlikely(rc < 0)) { fprintf(stderr, "Error: Could not read from file '%s' (%s)\n", f->name, strerror(errno)); + free(buf); return -1; } else if (rc < block_size) block_size = rc; for (i = 0; i < block_size; i++) { if (buf[i] == '\n') { - if (--n_lines == 0) + if (--n_lines == 0) { + free(buf); return offset + i + 1; + } } } offset += block_size; } + free(buf); return offset; } @@ -214,14 +241,16 @@ static off_t bytes_to_offset(struct file_struct *f, unsigned long n_bytes) static ssize_t tail_pipe(struct file_struct *f) { - ssize_t rc; - char buf[BUFFER_SIZE]; + ssize_t rc, buffer_size = f->st_blksize; + char *buf; + + buf = alloc_buffer(f); if (verbose) write_header(f->name); /* We will just tail everything here */ - while ((rc = read(f->fd, buf, BUFFER_SIZE)) > 0) { + while ((rc = read(f->fd, buf, buffer_size)) > 0) { if (write(STDOUT_FILENO, buf, (size_t) rc) < 0) { /* e.g. when writing to a pipe which gets closed */ fprintf(stderr, "Error: Could not write to stdout (%s)\n", strerror(errno)); @@ -229,6 +258,7 @@ static ssize_t tail_pipe(struct file_struct *f) } } + free(buf); return rc; } @@ -236,9 +266,12 @@ static int tail_file(struct file_struct *f, unsigned long n_units, char mode, ch { ssize_t bytes_read = 0; off_t offset = 0; - char buf[BUFFER_SIZE]; + char *buf; + ssize_t buffer_size; struct stat finfo; + buf = alloc_buffer(f); + if (strcmp(f->name, "-") == 0) f->fd = STDIN_FILENO; else { @@ -267,6 +300,7 @@ static int tail_file(struct file_struct *f, unsigned long n_units, char mode, ch return tail_pipe(f); f->st_size = finfo.st_size; + f->st_blksize = finfo.st_blksize; /* TODO: Can this value be 0 or negative? */ if (mode == M_LINES) offset = lines_to_offset(f, n_units); @@ -284,7 +318,8 @@ static int tail_file(struct file_struct *f, unsigned long n_units, char mode, ch lseek(f->fd, offset, SEEK_SET); - while ((bytes_read = read(f->fd, buf, BUFFER_SIZE)) > 0) + buffer_size = f->st_blksize; + while ((bytes_read = read(f->fd, buf, buffer_size)) > 0) write(STDOUT_FILENO, buf, (size_t) bytes_read); if (!forever) { @@ -302,15 +337,17 @@ static int handle_inotify_event(struct inotify_event *inev, struct file_struct * int ret = 0; if (inev->mask & IN_MODIFY) { - ssize_t rc; - char fbuf[BUFFER_SIZE]; + ssize_t rc, buffer_size = f->st_blksize; + char *fbuf; struct stat finfo; + fbuf = alloc_buffer(f); + if (verbose) write_header(f->name); lseek(f->fd, f->st_size, SEEK_SET); /* Old file size */ - while ((rc = read(f->fd, fbuf, BUFFER_SIZE)) != 0) + while ((rc = read(f->fd, fbuf, buffer_size)) != 0) write(STDOUT_FILENO, fbuf, (size_t) rc); if (fstat(f->fd, &finfo) < 0) { @@ -321,6 +358,7 @@ static int handle_inotify_event(struct inotify_event *inev, struct file_struct * f->st_size = finfo.st_size; + free(fbuf); return ret; } else if (inev->mask & IN_DELETE_SELF) { fprintf(stderr, "File '%s' deleted.\n", f->name); @@ -460,15 +498,21 @@ int main(int argc, char **argv) specified and standard input is a pipe. */ if (forever) { struct stat finfo; - if (fstat(STDIN_FILENO, &finfo) == 0 - && IS_PIPELIKE(finfo.st_mode)) + int rc = fstat(STDIN_FILENO, &finfo); + + if (rc == -1) { + fprintf(stderr, "Error: Could not stat stdin (%s)\n", strerror(errno)); + exit(EXIT_FAILURE); + } + + if (rc == 0 && IS_PIPELIKE(finfo.st_mode)) forever = 0; } } files = malloc(n_files * sizeof(struct file_struct)); if (unlikely(!files)) { - fprintf(stderr, "Error: Not enough memory (%s)\n", strerror(errno)); + fprintf(stderr, "Error: Could not allocate memory (%s)\n", strerror(errno)); exit(EXIT_FAILURE); } |