diff options
Diffstat (limited to 'lash.c')
| -rw-r--r-- | lash.c | 161 |
1 files changed, 123 insertions, 38 deletions
@@ -27,6 +27,7 @@ #define BB_FEATURE_SH_BACKTICKS +//#define BB_FEATURE_SH_IF_EXPRESSIONS @@ -55,6 +56,14 @@ enum redirectionType { REDIRECT_INPUT, REDIRECT_OVERWRITE, REDIRECT_APPEND }; +#define REGULAR_JOB_CONTEXT 0x1 +#define IF_EXP_CONTEXT 0x2 +#define THEN_EXP_CONTEXT 0x4 +#define ELSE_EXP_CONTEXT 0x8 + +enum jobContext { REGULAR_APP, IF_CONTEXT, THEN_CONTEXT +}; + struct jobSet { struct job *head; /* head of list of running jobs */ struct job *fg; /* current foreground job */ @@ -86,12 +95,12 @@ struct job { struct childProgram *progs; /* array of programs in job */ struct job *next; /* to track background commands */ int stoppedProgs; /* number of programs alive, but stopped */ + int jobContext; /* bitmask defining current context */ }; struct builtInCommand { char *cmd; /* name */ char *descr; /* description */ - char *usage; /* usage */ int (*function) (struct job *, struct jobSet * jobList); /* function ptr */ }; @@ -107,6 +116,12 @@ static int builtin_export(struct job *cmd, struct jobSet *junk); static int builtin_source(struct job *cmd, struct jobSet *jobList); static int builtin_unset(struct job *cmd, struct jobSet *junk); static int builtin_read(struct job *cmd, struct jobSet *junk); +#ifdef BB_FEATURE_SH_IF_EXPRESSIONS +static int builtin_if(struct job *cmd, struct jobSet *junk); +static int builtin_then(struct job *cmd, struct jobSet *junk); +static int builtin_else(struct job *cmd, struct jobSet *junk); +static int builtin_fi(struct job *cmd, struct jobSet *junk); +#endif /* function prototypes for shell stuff */ @@ -122,30 +137,38 @@ static int busy_loop(FILE * input); * can change global variables in the parent shell process but they will not * work with pipes and redirects; 'unset foo | whatever' will not work) */ static struct builtInCommand bltins[] = { - {"bg", "Resume a job in the background", "bg [%%job]", builtin_fg_bg}, - {"cd", "Change working directory", "cd [dir]", builtin_cd}, - {"exit", "Exit from shell()", "exit", builtin_exit}, - {"fg", "Bring job into the foreground", "fg [%%job]", builtin_fg_bg}, - {"jobs", "Lists the active jobs", "jobs", builtin_jobs}, - {"export", "Set environment variable", "export [VAR=value]", builtin_export}, - {"unset", "Unset environment variable", "unset VAR", builtin_unset}, - {"read", "Input environment variable", "read [VAR]", builtin_read}, - {NULL, NULL, NULL, NULL} + {"bg", "Resume a job in the background", builtin_fg_bg}, + {"cd", "Change working directory", builtin_cd}, + {"exit", "Exit from shell()", builtin_exit}, + {"fg", "Bring job into the foreground", builtin_fg_bg}, + {"jobs", "Lists the active jobs", builtin_jobs}, + {"export", "Set environment variable", builtin_export}, + {"unset", "Unset environment variable", builtin_unset}, + {"read", "Input environment variable", builtin_read}, + {NULL, NULL, NULL} }; /* Table of forking built-in functions (things that fork cannot change global * variables in the parent process, such as the current working directory) */ static struct builtInCommand bltins_forking[] = { - {"env", "Print all environment variables", "env", builtin_env}, - {"pwd", "Print current directory", "pwd", builtin_pwd}, - {".", "Source-in and run commands in a file", ". filename", builtin_source}, - {"help", "List shell built-in commands", "help", builtin_help}, - {NULL, NULL, NULL, NULL} + {"env", "Print all environment variables", builtin_env}, + {"pwd", "Print current directory", builtin_pwd}, +#ifdef BB_FEATURE_SH_IF_EXPRESSIONS + {"if", NULL, builtin_if}, + {"then", NULL, builtin_then}, + {"else", NULL, builtin_else}, + {"fi", NULL, builtin_fi}, +#endif + {".", "Source-in and run commands in a file", builtin_source}, + {"help", "List shell built-in commands", builtin_help}, + {NULL, NULL, NULL} }; static char *prompt = "# "; static char *cwd; static char *local_pending_command = NULL; +static char *promptStr = NULL; +static struct jobSet jobList = { NULL, NULL }; #ifdef BB_FEATURE_SH_COMMAND_EDITING void win_changed(int junk) @@ -256,9 +279,13 @@ static int builtin_help(struct job *dummy, struct jobSet *junk) fprintf(stdout, "\nBuilt-in commands:\n"); fprintf(stdout, "-------------------\n"); for (x = bltins; x->cmd; x++) { + if (x->descr==NULL) + continue; fprintf(stdout, "%s\t%s\n", x->cmd, x->descr); } for (x = bltins_forking; x->cmd; x++) { + if (x->descr==NULL) + continue; fprintf(stdout, "%s\t%s\n", x->cmd, x->descr); } fprintf(stdout, "\n\n"); @@ -339,6 +366,44 @@ static int builtin_read(struct job *cmd, struct jobSet *junk) return (res); } +#ifdef BB_FEATURE_SH_IF_EXPRESSIONS +/* Built-in handler for 'if' commands */ +static int builtin_if(struct job *cmd, struct jobSet *junk) +{ + cmd->jobContext |= IF_EXP_CONTEXT; + printf("Hit an if -- jobContext=%d\n", cmd->jobContext); + return TRUE; +} + +/* Built-in handler for 'then' (part of the 'if' command) */ +static int builtin_then(struct job *cmd, struct jobSet *junk) +{ + if (cmd->jobContext & IF_EXP_CONTEXT) { + fprintf(stderr, "unexpected token `then'\n"); + fflush(stderr); + return FALSE; + } + cmd->jobContext |= THEN_EXP_CONTEXT; + printf("Hit an then -- jobContext=%d\n", cmd->jobContext); + return TRUE; +} + +/* Built-in handler for 'else' (part of the 'if' command) */ +static int builtin_else(struct job *cmd, struct jobSet *junk) +{ + printf("Hit an else\n"); + cmd->jobContext |= ELSE_EXP_CONTEXT; + return TRUE; +} + +/* Built-in handler for 'fi' (part of the 'if' command) */ +static int builtin_fi(struct job *cmd, struct jobSet *junk) +{ + printf("Hit an fi\n"); + return TRUE; +} +#endif + /* Built-in '.' handler (read-in and execute commands from file) */ static int builtin_source(struct job *cmd, struct jobSet *junk) { @@ -471,7 +536,6 @@ static int getCommand(FILE * source, char *command) if (source == stdin) { #ifdef BB_FEATURE_SH_COMMAND_EDITING int len; - char *promptStr; len=fprintf(stdout, "%s %s", cwd, prompt); fflush(stdout); promptStr=(char*)xmalloc(sizeof(char)*(len+1)); @@ -587,8 +651,9 @@ static int parseCommand(char **commandPtr, struct job *job, struct jobSet *jobLi Getting clean memory relieves us of the task of NULL terminating things and makes the rest of this look a bit cleaner (though it is, admittedly, a tad less efficient) */ - job->cmdBuf = command = calloc(1, 2*strlen(*commandPtr) + 1); + job->cmdBuf = command = calloc(2*strlen(*commandPtr) + 1, sizeof(char)); job->text = NULL; + job->jobContext = REGULAR_JOB_CONTEXT; prog = job->progs; prog->numRedirections = 0; @@ -863,7 +928,7 @@ static int parseCommand(char **commandPtr, struct job *job, struct jobSet *jobLi static int runCommand(struct job *newJob, struct jobSet *jobList, int inBg, int outPipe[2]) { - struct job *job; + struct job *theJob; int i; int nextin, nextout; int pipefds[2]; /* pipefd[0] is for reading */ @@ -957,33 +1022,33 @@ static int runCommand(struct job *newJob, struct jobSet *jobList, int inBg, int newJob->pgrp = newJob->progs[0].pid; - /* find the ID for the job to use */ + /* find the ID for the theJob to use */ newJob->jobId = 1; - for (job = jobList->head; job; job = job->next) - if (job->jobId >= newJob->jobId) - newJob->jobId = job->jobId + 1; + for (theJob = jobList->head; theJob; theJob = theJob->next) + if (theJob->jobId >= newJob->jobId) + newJob->jobId = theJob->jobId + 1; - /* add the job to the list of running jobs */ + /* add the theJob to the list of running jobs */ if (!jobList->head) { - job = jobList->head = malloc(sizeof(*job)); + theJob = jobList->head = malloc(sizeof(*theJob)); } else { - for (job = jobList->head; job->next; job = job->next); - job->next = malloc(sizeof(*job)); - job = job->next; + for (theJob = jobList->head; theJob->next; theJob = theJob->next); + theJob->next = malloc(sizeof(*theJob)); + theJob = theJob->next; } - *job = *newJob; - job->next = NULL; - job->runningProgs = job->numProgs; - job->stoppedProgs = 0; + *theJob = *newJob; + theJob->next = NULL; + theJob->runningProgs = theJob->numProgs; + theJob->stoppedProgs = 0; if (inBg) { - /* we don't wait for background jobs to return -- append it - to the list of backgrounded jobs and leave it alone */ - printf("[%d] %d\n", job->jobId, + /* we don't wait for background theJobs to return -- append it + to the list of backgrounded theJobs and leave it alone */ + printf("[%d] %d\n", theJob->jobId, newJob->progs[newJob->numProgs - 1].pid); } else { - jobList->fg = job; + jobList->fg = theJob; /* move the new process group into the foreground */ /* suppress messages when run from /linuxrc mag@sysgo.de */ @@ -1037,7 +1102,6 @@ static int busy_loop(FILE * input) { char *command; char *nextCommand = NULL; - struct jobSet jobList = { NULL, NULL }; struct job newJob; pid_t parent_pgrp; int i; @@ -1070,7 +1134,8 @@ static int busy_loop(FILE * input) newJob.numProgs) { int pipefds[2] = {-1,-1}; runCommand(&newJob, &jobList, inBg, pipefds); - } else { + } + else { free(command); command = (char *) calloc(BUFSIZ, sizeof(char)); nextCommand = NULL; @@ -1079,7 +1144,7 @@ static int busy_loop(FILE * input) /* a job is running in the foreground; wait for it */ i = 0; while (!jobList.fg->progs[i].pid || - jobList.fg->progs[i].isStopped) i++; + jobList.fg->progs[i].isStopped == 1) i++; waitpid(jobList.fg->progs[i].pid, &status, WUNTRACED); @@ -1128,6 +1193,22 @@ static int busy_loop(FILE * input) } +#ifdef BB_FEATURE_CLEAN_UP +void free_memory(void) +{ + if (promptStr) + free(promptStr); + if (cwd) + free(cwd); + if (local_pending_command) + free(local_pending_command); + + if (jobList.fg && !jobList.fg->runningProgs) { + removeJob(&jobList, jobList.fg); + } +} +#endif + int shell_main(int argc, char **argv) { @@ -1137,6 +1218,10 @@ int shell_main(int argc, char **argv) cwd=(char*)xmalloc(sizeof(char)*MAX_LINE+1); getcwd(cwd, sizeof(char)*MAX_LINE); +#ifdef BB_FEATURE_CLEAN_UP + atexit(free_memory); +#endif + #ifdef BB_FEATURE_SH_COMMAND_EDITING cmdedit_init(); signal(SIGWINCH, win_changed); |